Technical contributor onboarding/Create accounts

Create accounts at:


 * Wikitech (needed for Phabricator and Gerrit): wikitech.wikimedia.org
 * Phabricator: phabricator.wikimedia.org
 * Gerrit: gerrit.wikimedia.org
 * Meta-Wiki (needed for MediaWiki): meta.wikimedia.org
 * You will not be able to create links to external sites for X days after creating the account. (TODO: find the value of X.)