Add comprehensive documentation for SnapForm features and workflows

- Introduced new guides for Depth Plane, Surface, and animation workflows.
- Added installation instructions and FAQs to assist users in setup and troubleshooting.
- Created a quick-start guide for first-time users to convert images to Depth Planes.
- Documented the process for removing backgrounds from images.
- Established a models and storage section to clarify data management.
- Included a stylesheets file for improved documentation styling.
- Updated mkdocs configuration for better navigation and theme settings.

docs/server.md

@@ -1,5 +1,8 @@
 # Job Server
 
+本页记录 Environment、模型缓存和 Job Runtime 的内部设计。安装或使用遇到问题时，请先查看
+[安装与首次配置](installation.md)和[常见问题](faq.md)。
+
 ## 运行架构
 
 SnapForm 在独立的 Python 3.12 Environment 中运行 HTTP Job Server，Blender 只通过标准库 HTTP Client 提交和轮询任务，不把计算依赖载入 Blender Python。Server 只监听 `127.0.0.1`，由外置 BlendJob wheel 提供的 `ServerController` 保存随机端口与 Instance ID；专属本地进程协议不使用额外 Token 鉴权。