chore: import upstream snapshot with attribution

docs/README.md

@@ -0,0 +1,35 @@
+# Documentation
+
+This folder contains the documentation source files for Spec Kit, built using [DocFX](https://dotnet.github.io/docfx/).
+
+## Building Locally
+
+To build the documentation locally:
+
+1. Install DocFX:
+
+   ```bash
+   dotnet tool install -g docfx
+   ```
+
+2. Build the documentation:
+
+   ```bash
+   cd docs
+   docfx docfx.json --serve
+   ```
+
+3. Open your browser to `http://localhost:8080` to view the documentation.
+
+## Structure
+
+- `docfx.json` - DocFX configuration file
+- `index.md` - Main documentation homepage
+- `toc.yml` - Table of contents configuration
+- `installation.md` - Installation guide
+- `quickstart.md` - Quick start guide
+- `_site/` - Generated documentation output (ignored by git)
+
+## Deployment
+
+Documentation is automatically built and deployed to GitHub Pages when changes are pushed to the `main` branch. The workflow is defined in `.github/workflows/docs.yml`.