[Feature request] op.gg rune source

[flowingice]

Is your feature request related to a problem? Please describe.
App can't download runes from op.gg.

Describe the solution you'd like
I will implement getting runes from op.gg.

Describe alternatives you've considered
Someone else could implement it.

Additional context
I'm new to working on somebody else's repositories on github so I'm not sure what's the proper way to signal that I will be working on a requested feature.
Card: https://github.com/stirante/RuneChanger/projects/1#card-45337262

[stirante]

Hey, thanks for contributing! If you want you could join our discord server (https://discord.gg/9tEsjhj) and we could talk about any contributions you want to make and also give you some more control over GitHub repo.

This project unfortunately doesn't get as much work from me as it should lately due to having no time, so I really appreciate your contributions.