Adapt to GH Actions; update navigation sidebar

.github/workflows/pages.yml

@@ -0,0 +1,73 @@
+# Taken from https://github.com/just-the-docs/just-the-docs-template/blob/main/README.md#hosting-your-docs-from-an-existing-project-repo
+
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+
+# Sample workflow for building and deploying a Jekyll site to GitHub Pages
+name: Deploy Jekyll site to Pages
+
+on:
+  push:
+    branches:
+      - "main"
+    paths:
+      - "docs/**"
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow one concurrent deployment
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  # Build job
+  build:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: docs
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.1' # Not needed with a .ruby-version file
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+          cache-version: 0 # Increment this number if you need to re-download cached gems
+          working-directory: '${{ github.workspace }}/docs'
+      - name: Setup Pages
+        id: pages
+        uses: actions/configure-pages@v3
+      - name: Build with Jekyll
+        # Outputs to the './_site' directory by default
+        run: bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}"
+        env:
+          JEKYLL_ENV: production
+      - name: Upload artifact
+        # Automatically uploads an artifact from the './_site' directory by default
+        uses: actions/upload-pages-artifact@v1
+        with:
+          path: "docs/_site/"
+
+  # Deployment job
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v2

docs/Gemfile

@@ -1,6 +1,9 @@
+# Copied from https://github.com/just-the-docs/just-the-docs-template/blob/main/Gemfile
+
 source "https://rubygems.org"
-gem "just-the-docs"
-gem "github-pages", group: :jekyll_plugins
-gem "jekyll-include-cache", group: :jekyll_plugins
-gem "json", "~> 2.7"
-gem "webrick", "~> 1.8"
+
+gem "jekyll", "~> 4.3.3" # installed by `gem jekyll`
+# gem "webrick"        # required when using Ruby >= 3 and Jekyll <= 4.2.2
+
+# gem "just-the-docs", "0.7.0" # pinned to the current release
+gem "just-the-docs"        # always download the latest release