[folding] snippets for folding markers

extensions/csharp/package.json

@@ -31,6 +31,10 @@
         "scopeName": "source.cs",
         "path": "./syntaxes/csharp.tmLanguage.json"
       }
-    ]
+    ],
+		"snippets": [{
+			"language": "csharp",
+			"path": "./snippets/csharp.json"
+		}]
   }
 }