feat: initial itpp-docs setup with MkDocs Material

- mkdocs.yml with dark slate theme, nav for 12 ITPP projects
- build-docs.sh aggregates docs from all project repos
- .gitea/workflows/docs-publish.yml for nightly rebuild+deploy
- README and CHANGELOG for the itpp-docs repo itself
- docs-source/ populated from all 12 repos
- site/ ready for deployment to docs.itpropartner.com

.gitea/workflows/docs-publish.yml

@@ -0,0 +1,20 @@
+name: Publish Docs Site
+on:
+  push:
+    branches: [main]
+  schedule:
+    - cron: '0 5 * * *'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build MkDocs site
+        run: |
+          pip install mkdocs mkdocs-material
+          bash build-docs.sh
+          mkdocs build
+      - name: Deploy to app3
+        run: |
+          rsync -avz site/ root@152.53.241.111:/var/www/docs.itpropartner.com/