New logo

The logo we have was kind of made in a hurry (took a couple hours) early on just so we'd have something. (Discussion in https://github.com/ActivityWatch/activitywatch/issues/9)

I've thought about this a bit, and have some ideas for an improvement.

Specifically:

- I want to get rid of the "watch" component, the name is confusing enough
- Edit: or maybe not? It doesn't really bother me anymore.
- I want a little (but not too much) color, definitely less white
- I think a sunburst would look pretty nice

I'm not going to hurry this like last time, but wanted to get this down.

---
Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/48648329-new-logo?utm_campaign=plugin&utm_content=tracker%2F35920020&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F35920020&utm_medium=issues&utm_source=github).

Start by reading the discussion linked from issue #9 and the design ideas recorded here. Confirm the intended direction with maintainers before working; done means an agreed replacement logo that addresses the unresolved watch component, color, and sunburst preferences.

Rédigé par le modèle d'indexation à partir du texte de l'issue.