chore: update typing file comments

Close #2714

Author: filipesilva

packages/angular-cli/blueprints/ng2/files/__path__/typings.d.ts

@@ -1,5 +1,4 @@
-// Typings reference file, see links for more information
-// https://github.com/typings/typings
+// Typings reference file, you can add your own global typings here
 // https://www.typescriptlang.org/docs/handbook/writing-declaration-files.html
 
 declare var System: any;