Fixes #17363 Adds typings.json schema (#17416)

extensions/typescript/package.json

@@ -287,6 +287,10 @@
 			{
 				"fileMatch": "tsconfig.json",
 				"url": "./schemas/tsconfig.schema.json"
+			},
+			{
+				"fileMatch": "typings.json",
+				"url": "http://json.schemastore.org/typings"
 			}
 		]
 	}