Update documentation.yml

Add YAML front matter to the generated documentation.  This should hopefully generate the directory structure we want.

Author: compnerd

.github/workflows/documentation.yml

@@ -70,6 +70,20 @@ jobs:
         swift doc generate Sources\SwiftWin32 --module-name SwiftWin32 --output site\SwiftWin32 --base-url https://compnerd.github.io/swift-win32/SwiftWin32
         swift doc generate Sources\SwiftWin32UI --module-name SwiftWin32UI --output site\SwiftWin32UI --base-url https://compnerd.github.io/swift-win32/SwiftWin32UI
 
+    - name: Post-Process
+      run: |
+        foreach ($module in "CoreGraphics","SwiftWin32","SwiftWin32UI") {
+          Get-ChildItem -Path site\$module -Recurse -File -Include "*.md" -Exclude _Footer.md,_Sidebar.md,index.md | ForEach-Object {
+            Set-Content $_.FullName -value @"
+            ---
+            layout: default
+            title: $(_.BaseName -replace '(?<=\w)_','.')
+            parent: $($_.Directory.BaseName)
+            ---
+            "@,$(Get-Content $_.FullName)
+          }
+        }
+
     - name: Deploy
       run: |
         git -C site add --all