add spell scaling!

[cmrtnll]

pretty much the only thing missing

[ThomasJClark]

Thanks for the suggestion. @jerpdoesgames already has an amazing tool that calculates spell scaling, including estimated boosts from spell school buffs

https://jerp.tv/eldenring/spelltools/

I think I'll hold off adding this because this tool already does a great job, and mine isn't specialized towards spellcasting related features.

[ThomasJClark]

Resolved by #9