new pages, responsive, update header & footer

[thomasza92]

Makes site responsive, adds the rest of our pages and updates the header and footer.

Closes https://github.com/steelesh/UCollab/issues/40

[steelesh]

@thomasza92 looks good!!

i like the nav drawer, there's some improvements i thought of that could be made in the future (not high priority, but some enhancements), lmk what you think:

• clicking outside closes it
• navigating to a different route closes it
• toggling it (clicking on the profile image again) closes/opens it

also, we could implement a global state management library for popups, dialogs, menus, drawers, etc. -- not needed now, but for when we develop more features and managing state gets increasingly difficult