HowToContribute instructions obsolete

The Solr HowToContribute page has obsolete instructions:

(1) “for very minor changes, spelling errors, grammar corrections and the like it's probably better to just comment on the live page rather than go through the heavyweight process of creating a JIRA and patch”. But the page is immutable. No method for commenting on it is apparent.

(2) “Contributors should join the Solr mailing lists.” The link to mailing lists is obsolete.