Google Code-in

The LinkFilter extension is using old API message formats, these should be replaced with i18n messages with entries in en.json and qqq.json

As well as message apihelp-linkfilter-description, descriptions for the 2 parameters, and one for the example is necessary

See https://www.mediawiki.org/wiki/API:Localisation for more information. Looking at many other extensions will also provide working examples. Such as https://github.com/wikimedia/mediawiki-extensions-CodeReview/blob/master/api/ApiCodeDiff.php#L73-L95 along with https://github.com/wikimedia/mediawiki-extensions-CodeReview/blob/master/i18n/en.json#L192-L195 and https://github.com/wikimedia/mediawiki-extensions-CodeReview/blob/master/i18n/qqq.json#L218-L221

See https://phabricator.wikimedia.org/T153238 for more task information including errors from Continous Integration