Tracking volume of games played over time alongside your stats

[NoseKnowsAll]

This is a suggested feature I saw originally on reddit that I agree would be awesome to see:

https://www.reddit.com/r/chess/comments/1efeqqm/i_wish_there_was_a_way_in_lichess_to_see_the/

Specifically, the idea is to add the ability to view the volume of games you have played over time to track the rating plot. It could be a bar chart or a line plot in my opinion, but perhaps the line plot is easier to implement. Here's an example image of what it could look like if you turn it on (blue is the currently implemented line, and red is the idea to implement):

[Bigguysahaj]

This would be so great !! I could raise a PR for this and we could go from there