Ontime v2 beta 6

Some small tidying up with focus on UX, could this be the last beta before going stable?

We also sneak in a feature to change timer style thanks to @kellhogs

What's Changed

• Feature: quick start by @cpvalente in #369
• Feat/timer/stylechange by @kellhogs in #341
• v2 beta5 modals by @cpvalente in #377
• v2 beta 5 by @cpvalente in #375
• Ux language by @cpvalente in #378
• v2 beta6 by @cpvalente in #379

Full Changelog: v2.0.0-beta5...v2.0.0-beta6