Update index.md - fixes typo

doc/development/fe_guide/index.md

@@ -11,7 +11,7 @@ across the GitLab frontend team.
 
 ## Overview
 
-GitLab is built on top of [Ruby on Rails](https://rubyonrails.org). It uses [Haml](https://haml.info/) and a JavaScript0based frontend with [Vue.js](https://vuejs.org).
+GitLab is built on top of [Ruby on Rails](https://rubyonrails.org). It uses [Haml](https://haml.info/) and a JavaScript-based frontend with [Vue.js](https://vuejs.org).
 <!-- vale gitlab.Spelling = NO -->
 Be wary of [the limitations that come with using Hamlit](https://github.com/k0kubun/hamlit/blob/master/REFERENCE.md#limitations).
 <!-- vale gitlab.Spelling = YES -->