Project details page "join the project" section

[alanmoo]

Might be modified if we launch without github auth

[kristinashu]

This is actually a phase 2 thing, as per https://docs.google.com/document/d/1SdyEca5EXwggJ8oZp9UstQ-tnHZ9_JiajW5K4WPGgdA/edit#

Removing from the milestone

[kristinashu]

Api work will happen here: #518

It should look like https://redpen.io/kf16f384972d804249

Same as on the old site, joining will:

• fork project in users github
• star project in users github
• if users 'introduce themselves' what they wrote should appear as a new ticket in the repo (not a required field)

User must be logged into site for this to happen. If they are not logged in then they see https://redpen.io/sm291d779b25ac292d

[hannahkane]

When we do this, be sure to use mofo-bootstrap for form styles