Turn links into links

CONTRIBUTING.md

@@ -22,34 +22,39 @@ Developer resources:
 
 Information regarding source code management, builds, coding standards, and more.
 
-- https://projects.eclipse.org/projects/eclipse.jdt.ui/developer
+- [https://projects.eclipse.org/projects/eclipse.jdt.ui/developer] [2]
 
 Contributor License Agreement:
 ------------------------------
 
 Before your contribution can be accepted by the project, you need to create and electronically sign the Eclipse Foundation Contributor License Agreement (CLA).
 
-- http://www.eclipse.org/legal/CLA.php
+- [http://www.eclipse.org/legal/CLA.php] [3]
 
 Contact:
 --------
 
 Contact the project developers via the project's "dev" list.
 
-- https://dev.eclipse.org/mailman/listinfo/jdt-ui-dev
+- [https://dev.eclipse.org/mailman/listinfo/jdt-ui-dev] [4]
 
 Search for bugs:
 ----------------
 
 This project uses Bugzilla to track ongoing development and issues.
 
-- https://bugs.eclipse.org/bugs/buglist.cgi?product=JDT;component=UI
+- [https://bugs.eclipse.org/bugs/buglist.cgi?product=JDT;component=UI] [5]
 
 Create a new bug:
 -----------------
 
 Be sure to search for existing bugs before you create another one. Remember that contributions are always welcome!
 
-- https://bugs.eclipse.org/bugs/enter_bug.cgi?product=JDT;component=UI
+- [https://bugs.eclipse.org/bugs/enter_bug.cgi?product=JDT;component=UI] [6]
 
 [1]: https://wiki.eclipse.org/JDT_UI/How_to_Contribute
+[2]: https://projects.eclipse.org/projects/eclipse.jdt.ui/developer
+[3]: http://www.eclipse.org/legal/CLA.php
+[4]: https://dev.eclipse.org/mailman/listinfo/jdt-ui-dev
+[5]: https://bugs.eclipse.org/bugs/buglist.cgi?product=JDT;component=UI
+[6]: https://bugs.eclipse.org/bugs/enter_bug.cgi?product=JDT;component=UI