[Feature Suggestion] Milestones

[isparks-tg]

It would be nice to be able to add milestones to the typing speed graph. Something like:

[aradzie]

At first I was going to dismiss this idea as too complex. But then I went for a walk and thought about it for a while. There seems to be a way to make it work, but it's still a significant chunk of work, so don't expect it soon.

The is awesome though!