Feature: Add Menu to site

[TanviHacks]

When logging into Divviup, you are taken to the Home/Accounts page. It would be nice to add a hamburger menu (three dashes on the upper left hand side) that lets you navigate to different parts of the page. Potentially with submenus for the different accounts to add members, add tasks, etc.

Also, right now the Home button looks clickable but clicking it doesn't actually redirect you. You end up back to Home/Accounts. So we should either make it unclickable (no a href, no blue underline), or take you to a different destination.

[jbr]

This would only be applicable once someone has selected an account, as we support multiple accounts per user. Will add for all pages within an account 👍