New "journal" tab on projects

I want to be able to just read someone's full journal, and nothing else. It'd be awesome if there was a different tab other than the timeline that was just the journal and only the journal

Start in the Rails project page and locate how the existing timeline tab is routed and rendered. Add a separate journal-only tab that displays the full journal without other timeline content, then verify that switching between the tabs preserves the intended views.

Written by the indexing model from the issue text.