fix(ci): Update GitHub Actions versions and add permissions

This commit updates the `.github/workflows/mkdocs.yml` file to use the latest versions of the `actions/checkout` and `actions/setup-python` actions.

Key changes:
- Upgraded `actions/checkout` from `v2` to `v4`.
- Upgraded `actions/setup-python` from `v2` to `v5`.
- Pinned the Python version to `'3.11'`.
- Added `permissions: contents: write` to the `deploy` job to ensure the workflow has the necessary permissions to publish to GitHub Pages.

.github/workflows/mkdocs.yml

@@ -0,0 +1,17 @@
+name: mkdocs
+on:
+  push:
+    branches:
+      - main
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+      - run: pip install mkdocs-material
+      - run: mkdocs gh-deploy --force

mkdocs.yml

@@ -0,0 +1,4 @@
+site_name: Borg Data Collector
+repo_url: https://github.com/Snider/Borg
+theme:
+  name: material