MKDocs conversion (#278)

Closes #252, Closes #250

## Changes
- ReplayWeb.page uses MKDocs for documentation now!
- Requires both
[`mkdocs-macros`](https://mkdocs-macros-plugin.readthedocs.io/en/latest/)
and [`mkdocs-redirects`]
(https://github.com/mkdocs/mkdocs-redirects) plugins to be installed
- Redirects existing docs pages to their new locations under either
`/embedding` or `/user-guide`
- Unused images have been removed
- Adds new ReplayWeb.page branding!

All pages have received copy edits. All references to future (or
previously) planned features have been removed. More major content
changes of note are as follows:

### Supported Locations
- Made into a page, no longer a table. Locations are either supported or
not listed.

### Offline Use 
- Removes browser cache section, adds improved PWA install and uninstall
instructions.
- Removes navigation instructions to GitHub's releases section in favour
of a link

### Supported Formats
- Moved to the User Guide homepage
- Updated the format support

### Exploring Archives
- Example links for showcasing features have been moved to their
respective feature documentation section on this page

### Remove Usage, Examples, and Troubleshooting Pages
- Usage content is covered in the user guide index
- Troubleshooting content has been added to a question section on the
getting started page about WARC vs WACZ.
- Examples are now Featured Projects on the docs homepage!

### Build Process
- Removes Jekyll & related site assets.
- Adds new GitHub action for publishing
- Adds a python macro to dynamically load the replayweb.page version from package.json
- Relocates replayweb.page site content under /site (including docs)
- Some assets (favicon, logo) and sw.js/ui.js automatically copied into /site

---------
Co-authored-by: Ilya Kreymer <ikreymer@gmail.com>

.github/workflows/gh-pages.yaml

@@ -1,86 +0,0 @@
-name: Deploy Jekyll + Webpack build to Pages
-
-on:
-  # Runs on pushes targeting the default branch
-  push:
-    branches: ["main"]
-
-  # 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 only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
-# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
-concurrency:
-  group: "pages"
-  cancel-in-progress: false
-
-jobs:
-  # Build job
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v3
-      - name: Detect package manager
-        id: detect-package-manager
-        run: |
-          if [ -f "${{ github.workspace }}/yarn.lock" ]; then
-            echo "manager=yarn" >> $GITHUB_OUTPUT
-            echo "command=install" >> $GITHUB_OUTPUT
-            echo "runner=yarn" >> $GITHUB_OUTPUT
-            exit 0
-          elif [ -f "${{ github.workspace }}/package.json" ]; then
-            echo "manager=npm" >> $GITHUB_OUTPUT
-            echo "command=ci" >> $GITHUB_OUTPUT
-            echo "runner=npx --no-install" >> $GITHUB_OUTPUT
-            exit 0
-          else
-            echo "Unable to determine package manager"
-            exit 1
-          fi
-      - name: Setup Node
-        uses: actions/setup-node@v3
-        with:
-          node-version: "18"
-          cache: ${{ steps.detect-package-manager.outputs.manager }}
-      - name: Setup Pages
-        uses: actions/configure-pages@v3
-      - name: Restore cache
-        uses: actions/cache@v3
-        with:
-          path: |
-            index.html
-            ui.js
-            node_modules/.cache/webpack/
-          key: ${{ runner.os }}-webpack-${{ hashFiles('**/package-lock.json', '**/yarn.lock') }}-${{ hashFiles('index.html', 'ui.js') }}
-          restore-keys: |
-            ${{ runner.os }}-webpack-${{ hashFiles('**/package-lock.json', '**/yarn.lock') }}-
-      - name: Install dependencies
-        run: ${{ steps.detect-package-manager.outputs.manager }} ${{ steps.detect-package-manager.outputs.command }}
-      - name: Build with Webpack
-        run: ${{ steps.detect-package-manager.outputs.runner }} build
-      - name: Build with Jekyll
-        uses: actions/jekyll-build-pages@v1
-        with:
-          source: ./
-          destination: ./_site
-      - name: Upload artifact
-        uses: actions/upload-pages-artifact@v2
-
-  # 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

.github/workflows/integration.yaml

@@ -2,6 +2,8 @@ name: Playwright Integration
 
 on:
   push:
+    paths-ignore:
+      - 'docs/**'
   pull_request:
 
 jobs:

.github/workflows/site-publish.yaml

@@ -0,0 +1,36 @@
+name: site-publish
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'site/**'
+      - 'mkdocs/**'
+
+permissions:
+  contents: write
+
+jobs:
+  deploy_site:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out Git repository
+        uses: actions/checkout@v3
+
+      - name: Install Node.js, NPM and Yarn
+        uses: actions/setup-node@v3
+        with:
+          node-version: 20
+          cache: 'yarn'
+
+      - name: Yarn Install
+        run: yarn install --frozen-lockfile
+
+      - name: Yarn Build
+        run: yarn build
+
+      - uses: actions/setup-python@v4
+        with:
+          python-version: 3.x
+      - run: pip install mkdocs-macros-plugin mkdocs-redirects mkdocs-material
+      - run: cd mkdocs && mkdocs gh-deploy --force