Rename CI workflow file and update docs requirements

Moved the CI workflow file to the correct '.github/workflows' directory. Added 'mkdocs-glightbox==0.40' to docs/requirements.txt for documentation enhancements.

.github/workflows/ci.yml

@@ -0,0 +1,31 @@
+name: ci 
+on:
+  push:
+    branches:
+      - master 
+      - main
+      - docs
+permissions:
+  contents: write
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Configure Git Credentials
+        run: |
+          git config user.name github-actions[bot]
+          git config user.email 41898282+github-actions[bot]@users.noreply.github.com
+      - uses: actions/setup-python@v5
+        with:
+          python-version: 3.x
+      - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV 
+      - uses: actions/cache@v4
+        with:
+          key: mkdocs-material-${{ env.cache_id }}
+          path: ~/.cache 
+          restore-keys: |
+            mkdocs-material-
+      - run: pip install mkdocs-material 
+      - run: cd docs
+      - run: mkdocs gh-deploy --force