feat(pwa): add basic manifest to allow installing

[robinjoseph08]

what

fixes #456, inspired by #482

• move manifest to top level and add necessary fields to make it installable
• add /profile route that will redirect you either to your profile or the login page
• [unrelated] move browserconfig.xml to the top level too since it seems like it should be there
• [unrelated] added /version route to the dev server so that the reload component doesn't show up all the time when developing