Add ChessBrowser to supported extensions

Will make it easier to review and test patches

Author: DannyS712

repositories.txt

@@ -3,6 +3,7 @@ mediawiki/extensions/AbuseFilter w/extensions/AbuseFilter
 mediawiki/extensions/BetaFeatures w/extensions/BetaFeatures
 mediawiki/extensions/CategoryTree w/extensions/CategoryTree
 mediawiki/extensions/CharInsert w/extensions/CharInsert
+mediawiki/extensions/ChessBrowser w/extensions/ChessBrowser
 mediawiki/extensions/Cite w/extensions/Cite
 mediawiki/extensions/CiteThisPage w/extensions/CiteThisPage
 mediawiki/extensions/Citoid w/extensions/Citoid