Make docs for Image.DISTORTION_METHODS Clearer

[MrKomodoDragon]

Hi, i was reading the docs for Image.DISTORTION_METHODS so that I could figure out the arguments each method would take so I could pass them into Image.distort(), but it’s hard to find the arguments. Could you possibly add them?

I’d be happy to make a PR for this, but I don’t know how.

[emcconville]

PR are welcome!

The documentation for distortion methods are located @ https://docs.wand-py.org/en/0.6.6/guide/distortion.html
I think only SRT, Perspective, and Affine are authored. Arc & Barrel distortion can easily be added. Each distortion algorithm are not finite, so documentation can be tricky without understanding the math involved. Anthony did a great job @ https://legacy.imagemagick.org/Usage/distorts/

[emcconville]

Docs updated w/ examples