corrected minor typo

Author: Chandan Rai

CONTRIBUTING.md

@@ -4,7 +4,7 @@
 
 - First identify where error is coming from. If it's occuring while running `vue` command then issue is indeed on
 `vue-cli` so please report it here. If error appears when you run one of `npm run` scripts, problem originates
-from a template you're using, [maybe one of the offical ones](https://github.com/vuejs-templates). If so, please
+from a template you're using, [maybe one of the official ones](https://github.com/vuejs-templates). If so, please
 open an issue on a template repository.
 
 - Try to search for your issue, it may have already been answered or even fixed in the development branch.