Thrive

After many years of working on this one - and using it every single day - I want
to publish this in a more professional way.

The version available right now at https://get-thriving.com is v1.1.0
and includes a large amount of improvements from the last year. Very soon
a MacOS, and hopefully iOS versions will come.

This version introduces:
* Settled on the name Thrive. Jupiter will remain the codename.
* Established a first visual identity, with font, color theme, logo, etc.
* Setup a landing site at https://get-thriving.com. The app itself lives at https://app.get-thriving.com. And the docs at https://docs.get-thriving.com. The site is hosted on Wix, and the docs are moved to render.io, same as the app. Stoped using "readthedocs".
* Basics of being a more public thing: privacy policy, terms of service, contact forms, some light CRM setup, cookie banners where appropriate, etc.
* Added the notion of [feature flags](../concepts/feature-flags.md).
* Added the large feature of [time plans](../concepts/time-plans.md).
* Added the large feature of [calendars](../concepts/calendar.md).
* Added the large feature of [gamification](../concepts/gamification.md).
* Added the Pomodoro timer tool.
* Add notes to all entities (like mini docs attached to them).
* Massive amount of bugfixes as incremental improvements.