Add GitHub Pages deployment workflow and upgrade Docusaurus

- Add GitHub Actions workflow for automated deployment to GitHub Pages
- Upgrade Docusaurus from 3.4.0 to 3.9.2 with latest features and bug fixes
- Upgrade React from 18.3.1 to 19.2.0 for improved performance
- Upgrade MDX and prism-react-renderer dependencies
- Add CNAME file for custom domain (www.apexfp.org)
- Fix deprecated onBrokenMarkdownLinks config for Docusaurus v4 compatibility

The workflow builds and deploys the documentation site automatically on pushes to main branch.

Author: ipavlic

peakconfig.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "instantiate": {
+      "classes": {
+        "Optional": ["Double", "Decimal", "SObject"]
+      }
+    }
+  }
+}