Remove unused files and update index and sidebar. (#19479)

docs/index.md

@@ -30,6 +30,8 @@ User-focused guides and tutorials for daily development workflows.
 
 - **[File management](./cli/tutorials/file-management.md):** How to work with
   local files and directories.
+- **[Get started with Agent skills](./cli/tutorials/skills-getting-started.md):**
+  Getting started with specialized expertise.
 - **[Manage context and memory](./cli/tutorials/memory-management.md):**
   Managing persistent instructions and facts.
 - **[Execute shell commands](./cli/tutorials/shell-commands.md):** Executing
@@ -40,8 +42,9 @@ User-focused guides and tutorials for daily development workflows.
   complex workflows.
 - **[Web search and fetch](./cli/tutorials/web-tools.md):** Searching and
   fetching content from the web.
-- **[Get started with skills](./cli/tutorials/skills-getting-started.md):**
-  Getting started with specialized expertise.
+- **[Set up an MCP server](./cli/tutorials/mcp-setup.md):** Set up an MCP
+  server.
+- **[Automate tasks](./cli/tutorials/automation.md):** Automate tasks.
 
 ## Features
 
@@ -92,10 +95,14 @@ Technical reference documentation for each capability of Gemini CLI.
   lookup for CLI features.
 - **[Memory (tool)](./tools/memory.md):** Storage details for persistent facts.
 - **[Model routing](./cli/model-routing.md):** Automatic fallback resilience.
-- **[Plan mode (experimental)](./cli/plan-mode.md):** Use a safe, read-only mode
-  for planning complex changes.
+- **[Plan mode 🧪](./cli/plan-mode.md):** Use a safe, read-only mode for
+  planning complex changes.
+- **[Remote subagents 🧪](./core/remote-agents.md):** Connecting to and using
+  remote agents.
 - **[Sandboxing](./cli/sandbox.md):** Isolate tool execution.
 - **[Shell (tool)](./tools/shell.md):** Detailed system execution parameters.
+- **[Subagents 🧪](./core/subagents.md):** Using specialized agents for specific
+  tasks.
 - **[Telemetry](./cli/telemetry.md):** Usage and performance metric details.
 - **[Todo (tool)](./tools/todos.md):** Progress tracking specification.
 - **[Token caching](./cli/token-caching.md):** Performance optimization.
@@ -127,14 +134,14 @@ Settings and customization options for Gemini CLI.
 
 Deep technical documentation and API specifications.
 
-- **[Architecture overview](./architecture.md):** System design and components.
 - **[Command reference](./cli/commands.md):** Detailed slash command guide.
 - **[Configuration reference](./get-started/configuration.md):** Settings and
   environment variables.
-- **[Core concepts](./core/concepts.md):** Fundamental terminology and
-  definitions.
 - **[Keyboard shortcuts](./cli/keyboard-shortcuts.md):** Productivity tips.
+- **[Memory import processor](./core/memport.md):** How Gemini CLI processes
+  memory from various sources.
 - **[Policy engine](./core/policy-engine.md):** Fine-grained execution control.
+- **[Tools API](./core/tools-api.md):** The API for defining and using tools.
 
 ## Resources
 
@@ -144,3 +151,19 @@ Support, release history, and legal information.
 - **[Changelogs](./changelogs/index.md):** Highlights and notable changes.
 - **[Quota and pricing](./quota-and-pricing.md):** Limits and billing details.
 - **[Terms and privacy](./tos-privacy.md):** Official notices and terms.
+
+## Development
+
+- **[Contribution guide](/docs/contributing):** How to contribute to Gemini CLI.
+- **[Integration testing](./integration-tests.md):** Running integration tests.
+- **[Issue and PR automation](./issue-and-pr-automation.md):** Automation for
+  issues and pull requests.
+- **[Local development](./local-development.md):** Setting up a local
+  development environment.
+- **[NPM package structure](./npm.md):** The structure of the NPM packages.
+
+## Releases
+
+- **[Release notes](./changelogs/index.md):** Release notes for all versions.
+- **[Stable release](./changelogs/latest.md):** The latest stable release.
+- **[Preview release](./changelogs/preview.md):** The latest preview release.