docs: sync documentation with post-v0.2 changes

CONTRIBUTING.md

@@ -7,7 +7,7 @@ Thank you for your interest in contributing! SkillOpt welcomes contributions of
 ```bash
 git clone https://github.com/microsoft/SkillOpt.git
 cd SkillOpt
-pip install -e ".[dev]"
+python -m pip install -e ".[dev,docs]"
 ```
 
 ## How to Contribute
@@ -16,23 +16,28 @@ pip install -e ".[dev]"
 Open a GitHub issue with reproduction steps, expected/actual behavior, and your config file (remove API keys).
 
 ### 🔧 Add a Benchmark
-See the [guide](docs/guide/new-benchmark.md) and use the scaffold at `skillopt/envs/_template/`.
+See the [guide](docs/guide/new-benchmark.md) and use the scaffold at
+`skillopt/envs/_template/`. Register the adapter lazily in both
+`scripts/train.py` and `scripts/eval_only.py`, and add focused tests.
 
 ### 🤖 Add a Model Backend
-See the [guide](docs/guide/new-backend.md).
+First check whether the built-in `openai_compatible` backend covers the
+provider. Otherwise follow the function-based backend contract in the
+[backend guide](docs/guide/new-backend.md), including routing, configuration,
+token accounting, and no-network tests.
 
 ### 📝 Improve Documentation
 ```bash
-pip install -e ".[docs]"
-mkdocs serve   # Preview at http://localhost:8000
+python -m mkdocs serve   # Preview at http://localhost:8000
 ```
 
 ## Pull Request Process
 
 1. Fork the repo and create a feature branch
-2. Make changes and test with an existing benchmark
+2. Make changes and run focused tests plus `python -m pytest -q`
 3. Submit a PR with a clear description
-4. Ensure CI passes
+4. For documentation changes, run `python -m mkdocs build --strict`
+5. Ensure CI passes
 
 ## Code Style
 - Follow existing patterns in the codebase