Update CI and docs to use submodules for maiko/notecards/loops/test

doHCFILES.yml: replace 5 separate checkout steps with a single
  checkout using submodules:true; remove now-redundant .git cleanup step.

buildLoadup.yml: add submodules:true to Checkout Medley; remove
  separate Checkout Notecards + tar steps (notecards.tgz was already
  commented out of the release push).

make-gh-pages.md: replace manual clone+copy instructions with
  git clone --recurse-submodules; remove rm -rf of submodule dirs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/buildLoadup.yml

@@ -124,6 +124,8 @@ jobs:
       # Checkout latest commit
       - name: Checkout Medley
         uses: actions/checkout@v4
+        with:
+          submodules: true
 
       # Setup release tag
       - name: Setup Release Tag
@@ -191,18 +193,6 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.MAIKO_TOKEN }}
 
-      # Checkout Notecards and tar it in the tarballsdir
-      - name: Checkout Notecards
-        uses: actions/checkout@v4
-        with:
-          repository: ${{ github.repository_owner }}/notecards
-          path: ./notecards
-      - name: Tar notecards into tarball dir
-        run: |
-          mv ./notecards ../notecards
-          cd ../notecards
-          git archive --format=tgz --output="${TARBALL_DIR}/notecards.tgz" --prefix=notecards/ main
-
       # Install vnc
       - name: Install vnc
         run: sudo apt-get update && sudo apt-get install -y tightvncserver