docs: Add initial docs

.github/workflows/docs-release.yaml

@@ -0,0 +1,65 @@
+name: "Docs: Release to GitHub pages"
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - '.ci/mkdocs/mkdocs.yaml'
+      - '.github/workflows/docs-release.yaml'
+      - "docs/**"
+
+jobs:
+  release-docs:
+    name: Release documentation
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Get GitHub API token
+        id: get-app-token
+        uses: getsentry/action-github-app-token@v1
+        with:
+          app_id: ${{ secrets.BJWS_APP_ID }}
+          private_key: ${{ secrets.BJWS_APP_PRIVATE_KEY }}
+
+      - name: Checkout charts branch
+        uses: actions/checkout@v3
+        with:
+          token: ${{ steps.get-app-token.outputs.token }}
+          path: "src"
+          fetch-depth: 0
+
+      - name: Checkout gh-pages branch
+        uses: actions/checkout@v3
+        with:
+          token: ${{ steps.get-app-token.outputs.token }}
+          path: "dest"
+          ref: "gh-pages"
+          fetch-depth: 0
+
+      - name: Install Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+
+      - name: Install mkdocs
+        shell: bash
+        working-directory: src
+        run: |
+          pip install -r ./.ci/mkdocs/requirements.txt
+
+      - name: Build documentation
+        shell: bash
+        working-directory: src
+        run: |
+          mkdocs build --config-file ./.ci/mkdocs/mkdocs.yaml -d "$PWD/../dest/docs"
+
+      - name: Commit changes
+        shell: bash
+        working-directory: dest
+        run: |
+          git config user.name "bjw-s-bot[bot]"
+          git config user.email "bjw-s-bot <87358111+bjw-s-bot[bot]@users.noreply.github.com>"
+          git add docs
+          git commit -m "Updated docs from ref: $GITHUB_SHA"
+          git push