Restructure docs into manual/development and add implementation docs (#94)

## Summary by Sourcery

Restructure documentation into separate manual and development sections,
introduce detailed internal implementation docs for auth/Java/mod
loaders, and update site navigation, landing page links, and MDX tooling
(Mermaid, card styling) to match the new structure and tech stack.

Enhancements:
- Enable Mermaid rendering support in the docs app and add a reusable
Mermaid React component.
- Refine Docs page rendering by customizing Card styling and removing
redundant in-page titles/descriptions rendered by the layout.
- Align docs source configuration and routing comments with the new
manual-based default paths.

Documentation:
- Split user-facing docs under a new manual section and move contributor
content into a dedicated development section for both English and
Chinese.
- Add comprehensive internal implementation documentation covering
authentication, Java management, mod loader/version merging, event bus,
and architecture patterns in both English and Chinese.
- Update existing feature docs (mod loaders, Java, authentication) and
getting-started/troubleshooting pages to be more conceptual, pointing to
implementation docs for technical details.
- Refresh architecture docs to reflect the React/Zustand frontend stack
and add Mermaid-based architecture diagrams.
- Adjust navigation labels, home-page CTAs, and doc links to target the
new manual/development structure and routes.

---------

Co-authored-by: 简律纯 <i@jyunko.cn>

1 files changed, 164 insertions, 0 deletions

diff --git a/packages/docs/content/en/manual/getting-started.mdx b/packages/docs/content/en/manual/getting-started.mdx
new file mode 100644
index 0000000..c172289
--- /dev/null
+++ b/packages/docs/content/en/manual/getting-started.mdx
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+---
+title: Getting Started
+description: Quick start guide to using DropOut Minecraft Launcher
+---
+
+# Getting Started
+
+DropOut is a modern, reproducible, and developer-grade Minecraft launcher built with Tauri v2 and Rust. This guide will help you get started with installing and using DropOut.
+
+## Installation
+
+### Download Pre-built Binaries
+
+Download the latest release for your platform from the [Releases](https://github.com/HsiangNianian/DropOut/releases) page.
+
+| Platform       | Files               |
+| -------------- | ------------------- |
+| Linux x86_64   | `.deb`, `.AppImage` |
+| Linux ARM64    | `.deb`, `.AppImage` |
+| macOS ARM64    | `.dmg`              |
+| Windows x86_64 | `.msi`, `.exe`      |
+| Windows ARM64  | `.msi`, `.exe`      |
+
+### Linux Installation
+
+#### Using .deb Package
+
+```bash
+sudo dpkg -i dropout_*.deb
+# Fix dependencies if needed
+sudo apt-get install -f
+```
+
+#### Using AppImage
+
+```bash
+chmod +x dropout_*.AppImage
+./dropout_*.AppImage
+```
+
+### macOS Installation
+
+1. Open the downloaded `.dmg` file
+2. Drag DropOut to your Applications folder
+3. If you see a security warning, go to System Preferences → Security & Privacy and allow the app
+
+### Windows Installation
+
+#### Using .msi Installer
+
+1. Double-click the `.msi` file
+2. Follow the installation wizard
+3. Launch DropOut from the Start Menu
+
+#### Using .exe Portable
+
+1. Double-click the `.exe` file
+2. DropOut will run directly without installation
+
+## First Launch
+
+When you first launch DropOut, you'll need to:
+
+1. **Choose Authentication Method**
+   - **Microsoft Account**: Recommended for official Minecraft
+   - **Offline Mode**: For testing or offline play
+
+2. **Configure Java Runtime**
+   - DropOut will automatically detect installed Java versions
+   - You can download Java directly from the launcher if needed
+
+3. **Select Minecraft Version**
+   - Browse available Minecraft versions
+   - Choose vanilla or modded versions (Fabric/Forge)
+
+## Quick Start Tutorial
+
+### 1. Login
+
+<Cards>
+  <Card title="Microsoft Account" description="Login with your official Minecraft account" />
+  <Card title="Offline Mode" description="Create a local profile for offline play" />
+</Cards>
+
+**Microsoft Login:**
+
+1. Click "Login with Microsoft"
+2. A device code will be displayed
+3. Visit the URL shown and enter the code
+4. Authorize the application
+5. Return to DropOut - you'll be logged in automatically
+
+**Offline Login:**
+
+1. Click "Offline Mode"
+2. Enter a username
+3. Click "Create Account"
+
+### 2. Install Minecraft
+
+1. Navigate to the **Versions** tab
+2. Browse available Minecraft versions
+3. Click on a version to install it
+4. Wait for the download to complete
+
+### 3. Launch the Game
+
+1. Go to the **Home** tab
+2. Select your desired version from the dropdown
+3. Adjust settings if needed:
+   - Memory allocation (RAM)
+   - Window resolution
+   - Java path
+4. Click **"Launch Game"**
+5. Monitor the launch process in the console
+
+## Next Steps
+
+<Cards>
+  <Card
+    title="Features"
+    href="/docs/manual/features"
+    description="Learn about all the features DropOut offers"
+  />
+  <Card
+    title="Instances"
+    href="/docs/manual/features/instances"
+    description="Create isolated game environments"
+  />
+  <Card
+    title="Mod Loaders"
+    href="/docs/manual/features/mod-loaders"
+    description="Install and manage Fabric and Forge"
+  />
+  <Card
+    title="Troubleshooting"
+    href="/docs/troubleshooting"
+    description="Common issues and solutions"
+  />
+</Cards>
+
+## System Requirements
+
+### Minimum Requirements
+
+- **OS**: Windows 10+, macOS 11+, or Linux (Debian-based)
+- **RAM**: 4GB (8GB recommended for modded Minecraft)
+- **Storage**: 2GB for launcher + game files
+- **Java**: Auto-installed by DropOut if not found
+
+### Recommended Requirements
+
+- **OS**: Latest stable version of your OS
+- **RAM**: 16GB for optimal performance with mods
+- **Storage**: 10GB+ for multiple versions and mods
+- **Java**: Java 17 or 21 (managed by DropOut)
+
+## Getting Help
+
+If you encounter issues:
+
+- Check the [Troubleshooting Guide](/docs/troubleshooting)
+- Report bugs on [GitHub Issues](https://github.com/HsiangNianian/DropOut/issues)
+- Join our community discussions