docs(detached-note): add comprehensive API reference and user guide

Add API.md (3200+ lines) with complete REST API documentation covering authentication, repository management, issues, pull requests, organizations, package registry, Actions, and Vault APIs. Includes code examples and error handling.

Add GUIDE.md with user-focused documentation for getting started, repository operations, collaboration workflows, and CI/CD setup.

Implement documentation tab in repository view with automatic detection and rendering of API.md and GUIDE.md files alongside README. Add locale strings and template for doc tab navigation.

options/locale/locale_en-US.json

@@ -1004,6 +1004,8 @@
   "repo.readme": "README",
   "repo.readme_helper": "Select a README file template.",
   "repo.readme_helper_desc": "This is the place where you can write a complete description for your project.",
+  "repo.guide": "User Guide",
+  "repo.api_doc": "API",
   "repo.auto_init": "Initialize Repository (Adds .gitignore, License and README)",
   "repo.trust_model_helper": "Select trust model for signature verification. Possible options are:",
   "repo.trust_model_helper_collaborator": "Collaborator: Trust signatures by collaborators",

routers/web/repo/view_home.go

@@ -14,6 +14,7 @@ import (
 
 	"code.gitcaddy.com/server/v3/models/db"
 	git_model "code.gitcaddy.com/server/v3/models/git"
+	"code.gitcaddy.com/server/v3/models/renderhelper"
 	repo_model "code.gitcaddy.com/server/v3/models/repo"
 	unit_model "code.gitcaddy.com/server/v3/models/unit"
 	user_model "code.gitcaddy.com/server/v3/models/user"
@@ -23,6 +24,7 @@ import (
 	"code.gitcaddy.com/server/v3/modules/httplib"
 	"code.gitcaddy.com/server/v3/modules/json"
 	"code.gitcaddy.com/server/v3/modules/log"
+	"code.gitcaddy.com/server/v3/modules/markup/markdown"
 	"code.gitcaddy.com/server/v3/modules/plugins"
 	repo_module "code.gitcaddy.com/server/v3/modules/repository"
 	"code.gitcaddy.com/server/v3/modules/setting"
@@ -259,6 +261,62 @@ func isGalleryImageFile(filename string) bool {
 	return false
 }
 
+// prepareHomeDocTab loads a markdown doc file for a named tab on the repo home page.
+// keyPrefix is used to namespace context data (e.g. "Guide" → "GuideTabExist", "GuideTabContent").
+func prepareHomeDocTab(ctx *context.Context, filename, keyPrefix string) {
+	ctx.Data[keyPrefix+"TabExist"] = false
+
+	if ctx.Repo.Repository.IsEmpty {
+		return
+	}
+
+	commit := ctx.Repo.Commit
+	if commit == nil {
+		return
+	}
+
+	entry, err := commit.GetTreeEntryByPath(filename)
+	if err != nil || entry.IsDir() {
+		return
+	}
+
+	ctx.Data[keyPrefix+"TabExist"] = true
+	ctx.Data[keyPrefix+"TabFileName"] = filename
+
+	// Load content
+	content, err := entry.Blob().GetBlobContent(setting.UI.MaxDisplayFileSize)
+	if err != nil {
+		log.Error("prepareHomeDocTab(%s): GetBlobContent: %v", filename, err)
+		return
+	}
+
+	// Render markdown using the full markup pipeline
+	rctx := renderhelper.NewRenderContextRepoFile(ctx, ctx.Repo.Repository, renderhelper.RepoFileOptions{
+		CurrentRefPath:  ctx.Repo.RefTypeNameSubURL(),
+		CurrentTreePath: ".",
+	}).WithMarkupType("markdown").WithRelativePath(filename)
+
+	rendered, err := markdown.RenderString(rctx, content)
+	if err != nil {
+		log.Error("prepareHomeDocTab(%s): RenderString: %v", filename, err)
+		ctx.Data[keyPrefix+"TabContent"] = content
+		ctx.Data[keyPrefix+"TabIsMarkdown"] = false
+		return
+	}
+	ctx.Data[keyPrefix+"TabContent"] = rendered
+	ctx.Data[keyPrefix+"TabIsMarkdown"] = true
+}
+
+// prepareHomeGuideTab loads GUIDE.md for the User Guide tab
+func prepareHomeGuideTab(ctx *context.Context) {
+	prepareHomeDocTab(ctx, "GUIDE.md", "Guide")
+}
+
+// prepareHomeAPIDocTab loads API.md for the API tab
+func prepareHomeAPIDocTab(ctx *context.Context) {
+	prepareHomeDocTab(ctx, "API.md", "APIDoc")
+}
+
 func prepareToRenderDirectory(ctx *context.Context) {
 	entries := renderDirectoryFiles(ctx, 1*time.Second)
 	if ctx.Written() {
@@ -594,6 +652,8 @@ func Home(ctx *context.Context) {
 			prepareUpstreamDivergingInfo,
 			prepareHomeSidebarLicenses,
 			prepareHomeLicenseTab,
+			prepareHomeGuideTab,
+			prepareHomeAPIDocTab,
 			prepareHomeGalleryTab,
 			prepareHomeSidebarCitationFile(entry),
 			prepareHomeSidebarLanguageStats,

templates/repo/view_content.tmpl

@@ -130,43 +130,64 @@
 		{{template "repo/code/upstream_diverging_info" .}}
 	{{end}}
 	{{template "repo/view_list" .}}
-	{{/* Tabs for Readme, License, Gallery - only shown at repo root */}}
+	{{/* Tabs for Readme, Guide, API, License, Gallery - only shown at repo root */}}
-	{{if and $isTreePathRoot (or (and .ReadmeExist (or .IsMarkup .IsPlainText)) .LicenseTabExist .GalleryTabExist)}}
+	{{$hasReadme := and .ReadmeExist (or .IsMarkup .IsPlainText)}}
+	{{if and $isTreePathRoot (or $hasReadme .GuideTabExist .APIDocTabExist .LicenseTabExist .GalleryTabExist)}}
 		<div class="ui top attached tabular menu" id="repo-home-tabs">
-			{{if and .ReadmeExist (or .IsMarkup .IsPlainText)}}
+			{{if $hasReadme}}
 			<a class="active item" data-tab="readme">
 				{{svg "octicon-book" 16}} {{ctx.Locale.Tr "repo.readme"}}
 			</a>
 			{{end}}
+			{{if .GuideTabExist}}
+			<a class="{{if not $hasReadme}}active {{end}}item" data-tab="guide">
+				{{svg "octicon-mortar-board" 16}} {{ctx.Locale.Tr "repo.guide"}}
+			</a>
+			{{end}}
+			{{if .APIDocTabExist}}
+			<a class="{{if and (not $hasReadme) (not .GuideTabExist)}}active {{end}}item" data-tab="apidoc">
+				{{svg "octicon-plug" 16}} {{ctx.Locale.Tr "repo.api_doc"}}
+			</a>
+			{{end}}
 			{{if .LicenseTabExist}}
-			<a class="{{if not (and .ReadmeExist (or .IsMarkup .IsPlainText))}}active {{end}}item" data-tab="license">
+			<a class="{{if and (not $hasReadme) (not .GuideTabExist) (not .APIDocTabExist)}}active {{end}}item" data-tab="license">
 				{{svg "octicon-law" 16}} {{ctx.Locale.Tr "repo.license"}}
 			</a>
 			{{end}}
 			{{if .GalleryTabExist}}
-			<a class="{{if and (not (and .ReadmeExist (or .IsMarkup .IsPlainText))) (not .LicenseTabExist)}}active {{end}}item" data-tab="gallery">
+			<a class="{{if and (not $hasReadme) (not .GuideTabExist) (not .APIDocTabExist) (not .LicenseTabExist)}}active {{end}}item" data-tab="gallery">
 				{{svg "octicon-image" 16}} {{ctx.Locale.Tr "repo.gallery"}}
 			</a>
 			{{end}}
 		</div>
 		<div class="ui bottom attached segment tw-p-0">
-			{{if and .ReadmeExist (or .IsMarkup .IsPlainText)}}
+			{{if $hasReadme}}
 			<div class="ui active tab" data-tab="readme">
 				{{template "repo/view_file" .}}
 			</div>
 			{{end}}
+			{{if .GuideTabExist}}
+			<div class="ui {{if not $hasReadme}}active {{end}}tab" data-tab="guide">
+				{{template "repo/view_doc_tab" dict "ctxData" . "FileName" .GuideTabFileName "Content" .GuideTabContent "IsMarkdown" .GuideTabIsMarkdown "Icon" "octicon-mortar-board"}}
+			</div>
+			{{end}}
+			{{if .APIDocTabExist}}
+			<div class="ui {{if and (not $hasReadme) (not .GuideTabExist)}}active {{end}}tab" data-tab="apidoc">
+				{{template "repo/view_doc_tab" dict "ctxData" . "FileName" .APIDocTabFileName "Content" .APIDocTabContent "IsMarkdown" .APIDocTabIsMarkdown "Icon" "octicon-plug"}}
+			</div>
+			{{end}}
 			{{if .LicenseTabExist}}
-			<div class="ui {{if not (and .ReadmeExist (or .IsMarkup .IsPlainText))}}active {{end}}tab" data-tab="license">
+			<div class="ui {{if and (not $hasReadme) (not .GuideTabExist) (not .APIDocTabExist)}}active {{end}}tab" data-tab="license">
 				{{template "repo/view_license_tab" .}}
 			</div>
 			{{end}}
 			{{if .GalleryTabExist}}
-			<div class="ui {{if and (not (and .ReadmeExist (or .IsMarkup .IsPlainText))) (not .LicenseTabExist)}}active {{end}}tab" data-tab="gallery">
+			<div class="ui {{if and (not $hasReadme) (not .GuideTabExist) (not .APIDocTabExist) (not .LicenseTabExist)}}active {{end}}tab" data-tab="gallery">
 				{{template "repo/view_gallery_tab" .}}
 			</div>
 			{{end}}
 		</div>
-	{{else if and .ReadmeExist (or .IsMarkup .IsPlainText)}}
+	{{else if $hasReadme}}
 		{{/* Fallback: show README without tabs if it's the only content */}}
 		{{template "repo/view_file" .}}
 	{{end}}

templates/repo/view_doc_tab.tmpl

@@ -0,0 +1,27 @@
+<div class="file-view code-view">
+	<div class="file-header tw-flex tw-items-center tw-justify-between">
+		<div class="file-header-left tw-flex tw-items-center">
+			{{svg .Icon 18 "tw-mr-2"}}
+			<strong>{{.FileName}}</strong>
+		</div>
+		<div class="file-header-right">
+			<a class="ui basic tiny button" href="{{.ctxData.RepoLink}}/src/{{.ctxData.RefTypeNameSubURL}}/{{.FileName}}">
+				{{svg "octicon-file" 14}} {{ctx.Locale.Tr "repo.view_file"}}
+			</a>
+			<a class="ui basic tiny button" href="{{.ctxData.RepoLink}}/raw/{{.ctxData.RefTypeNameSubURL}}/{{.FileName}}">
+				{{svg "octicon-code" 14}} {{ctx.Locale.Tr "repo.file_raw"}}
+			</a>
+		</div>
+	</div>
+	<div class="file-body tw-p-4 tw-text-base">
+		{{if .IsMarkdown}}
+		<div class="markup markdown">
+			{{.Content}}
+		</div>
+		{{else}}
+		<div class="file-content plain-text">
+			<pre>{{.Content}}</pre>
+		</div>
+		{{end}}
+	</div>
+</div>