Remove link title text that breaks rendered HTML at /handbook/communication/#user-communication-guidelines.

A Markdown link with a pipe in the title text renders as expected in the Web IDE preview, but it is interpreted as part of a table when the site is actually generated (either locally or for deployment to about.gitlab.com). Escaping and entity-encoding don't work as desired with Middleman*, so I'm removing the title text for the relevant link under /handbook/communication/#user-communication-guidelines for now.

While I'm at it I'm making the link relative too.

* If the pipe character is either escaped (\|) or entity-encoded (|) the link title looks fine in the Web IDE preview but every character shows on Middleman-generated pages.