Added AppMetadata type to the docgen toc (#563)

Author: hiranya911

docgen/content-sources/node/toc.yaml

@@ -165,6 +165,8 @@ toc:
     path: /docs/reference/admin/node/admin.projectManagement.AndroidApp
   - title: "AndroidAppMetadata"
     path: /docs/reference/admin/node/admin.projectManagement.AndroidAppMetadata
+  - title: "AppMetadata"
+    path: /docs/reference/admin/node/admin.projectManagement.AppMetadata
   - title: "IosApp"
     path: /docs/reference/admin/node/admin.projectManagement.IosApp
   - title: "IosAppMetadata"