Sphinx docs generation (#22697)

* add sphinx

* switch theme

* Experiment: sphinx docs generation updated (#22708)

* moved build to root gitignore, added .gitkeep

* Improved makefile doc build process

- Removed auto-generated docs from source control
- Moved apidoc.sh into Makefile
- Removed make.bat (can add back if Windows support desired)
- Added sphinx viewcode and markdown extensions
- Added feature to source /docs in build, so any .rst file in /docs will
  override the respective file during the build process
- Added feature to copy all markdown/rst files from source into /build/
  during build process so they can be easily referenced while writing
  docs (see examples in index.md)
- Wrote basic starter index.md file

TODO: Add new dependencies to Pipfile [dev-packages]

* Revert accidental modification to Pipfile

* fix command substitution

* exclude xx

* improve docs

* dont include all docs in release build

* Add dockerfile

* update title

* include normal readme

* build container in CI

* use buildkit

* add login

Co-authored-by: Chad Bailey <chadbailey904@gmail.com>
old-commit-hash: b816b5b644

.github/workflows/selfdrive_tests.yaml

@@ -314,3 +314,22 @@ jobs:
                         coverage run selfdrive/test/test_models.py"
     - name: Upload coverage to Codecov
       run: bash <(curl -s https://codecov.io/bash) -v -F test_car_models
+
+  docs:
+    name: build docs
+    runs-on: ubuntu-20.04
+    timeout-minutes: 50
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+    - name: Build docker container
+      run: |
+        docker pull $DOCKER_REGISTRY/$BASE_IMAGE:latest || true
+        docker pull $DOCKER_REGISTRY/openpilot-docs:latest || true
+        DOCKER_BUILDKIT=1 docker build --cache-from $DOCKER_REGISTRY/openpilot-docs:latest -t $DOCKER_REGISTRY/openpilot-docs:latest -f docs/docker/Dockerfile .
+    - name: Push docker container
+      if: github.ref == 'refs/heads/master' && github.event_name != 'pull_request' && github.repository == 'commaai/openpilot'
+      run: |
+        $DOCKER_LOGIN
+        docker push $DOCKER_REGISTRY/openpilot-docs:latest