docs: fix README.md (#33142)

* md

* Update README.md

* rename

* exclude

* Update README.md
old-commit-hash: 086dcfe715985447fa33f120d16a496309718ba2

docs/README.md

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+# openpilot docs
+
+This is the source for [docs.comma.ai](https://docs.comma.ai).
+The site is updated on pushes to master by this [workflow](../.github/workflows/docs.yaml).
+
+## Development
+NOTE: Those commands must be run in the root directory of openpilot, **not /docs**
+
+**1. Install the docs dependencies**
+``` bash
+pip install .[docs]
+```
+
+**2. Build the new site**
+``` bash
+mkdocs build
+```
+
+**3. Run the new site locally**
+``` bash
+mkdocs serve
+```
+
+References:
+* https://www.mkdocs.org/getting-started/
+* https://github.com/ntno/mkdocs-terminal