Minor changes to the tiers (Patreon)

I did some quick and small updates to the patreon tiers, removed stuff that I dont do all that consistently anymore.

For Bronze:
- You get to see some WIPS of stuff I plan to finish such as commission or personal work.

For silver
- I removed the sketch pack reward since I dont seem to do enough sketches per week.
- You will get to download the art packs I put on Gumroad.