[Regression] Useless Toon Shading Option

[sylv256]

Describe the bug: The toon shading option is useless. Either re-implement it, or remove it from the options and the README.md.

Where/when the bug happens or doesn't happen: ...

Screenshots or link to video: ...

Environment:

• Lumi Lights release version or link to commit: ...
• Canvas debug info from latest.log [see example]:

(paste here)

Content of .minecraft/canvas_shader_debug/failed/ if present (put "N/A" otherwise): ...

Additional context: Removed in commit 1c102a7