use link labels in component-readme markdown

build/component-readme.md

@@ -2,6 +2,11 @@
 FullCalendar Component
 ======================
 
-This repo is the official [Bower](http://twitter.github.com/bower/) component endpoint for the [FullCalendar Project](http://arshaw.com/fullcalendar/). It is a shim repo that has been generated by running the `grunt component` command in the main development repo.
+This repo is the official [Bower][bower] component endpoint for the [FullCalendar Project][fc-homepage]. It is a shim repo that has been generated by running the `grunt component` command in the main development repo.
 
-[Visit the development repo](https://github.com/arshaw/fullcalendar)
+[Visit the development repo][fc-repo]
+
+
+[bower]: http://bower.io/
+[fc-homepage]: http://arshaw.com/fullcalendar/
+[fc-repo]: https://github.com/arshaw/fullcalendar