feat: slim readme + ci site deployment

README: 11141 -> 43 lines. Details on the MkDocs site.
generate_readme.py: 444 -> 164 lines. Slim coverage table only.
build.yml: adds mkdocs-material install, generate_site.py, gh-deploy.
Adds pages: write permission for GitHub Pages deployment.

CONTRIBUTING.md

@@ -1,51 +1,14 @@
-# Contributing BIOS Files
+# Contributing to RetroBIOS
 
-Thank you for helping expand the BIOS collection!
+## Add a BIOS file
 
-## How to Contribute
+1. Fork this repository
+2. Place the file in `bios/Manufacturer/Console/filename`
+3. Variants (alternate hashes): `bios/Manufacturer/Console/.variants/`
+4. Create a Pull Request - checksums are verified automatically
 
-1. **Fork** this repository
-2. **Add** your BIOS file to the correct directory under `bios/Manufacturer/Console/`
-3. **Create a Pull Request**
+## File conventions
 
-## File Placement
-
-Place files in the correct manufacturer/console directory:
-```
-bios/
-├── Sony/
-│   └── PlayStation/
-│       └── scph5501.bin
-├── Nintendo/
-│   └── Game Boy Advance/
-│       └── gba_bios.bin
-└── Sega/
-    └── Dreamcast/
-        └── dc_boot.bin
-```
-
-## Verification
-
-All submitted BIOS files are automatically verified against known checksums:
-
-1. **Hash verification** - SHA1/MD5 checked against known databases
-2. **Size verification** - File size matches expected value
-3. **Platform reference** - File must be referenced in at least one platform config
-4. **Duplicate detection** - Existing files are flagged to avoid duplication
-
-## What We Accept
-
-- **Verified BIOS dumps** with matching checksums from known databases
-- **System firmware** required by emulators
-- **New variants** of existing BIOS files (different regions, versions)
-
-## What We Don't Accept
-
-- Game ROMs or ISOs
-- Modified/patched BIOS files
-- Files without verifiable checksums
-- Executable files (.exe, .bat, .sh)
-
-## Questions?
-
-Open an [Issue](../../issues) if you're unsure about a file.
+- Files >50 MB go in GitHub release assets (`large-files` release)
+- RPG Maker and ScummVM directories are excluded from deduplication
+- See the [documentation site](https://abdess.github.io/retrobios/) for full details