Apply responsive design for Contributors graphs.

What does this MR do?

Makes the Contributors graphs work on mobile.

Are there points in the code the reviewer needs to double check?

That this doesn't break on any screen sizes.

Why was this MR needed?

It used to be squished and impossible to read.

What are the relevant issue numbers?

Fixes #18845 (closed).

Screenshots (if relevant)

Before:

After:

cc: @jschatz1