Update CONTRIBUTING.md

Author: beshur

CONTRIBUTING.md

@@ -7,7 +7,7 @@ We don't do regular releases, only when some bugfixes or new stuff is ready.
 ## Service Requests
 Service requests are the new streaming services we are willing to add. The related issues have [service-request](https://github.com/stoplay/stoplay-ext/issues?q=is%3Aissue+is%3Aopen+label%3Aservice-request) label on them.
 
-This type of issues mean, that specific code for that web-site is needed to be added to the `src/content/index.js`.
+This type of issues means that specific code for that web-site is needed to be added to the `src/content/index.js`.
 
 ## (Git) flow
 1. Create a branch with the name {feature or bugfix}/{issue ID}-{short description} (forked off **origin/develop**). E.g. feature/51-mubert for [#51 Add http://play.mubert.com/ support](../issues/51)