Font size option

[capnmidnight]

The username labels are really hard to see.

[capnmidnight]

Reopening this issue because the font sizes are now kinda too large. Also, maybe we don't need to always show the user name on an avatar.

Maybe user name should only appear

• [ ] when the user speaks
• [ ] when the mouse hovers over the avatar
• [ ] when the user touches an avatar

And fades away after X seconds (3?)