docs: Update casing of `Ty` to `ty` (#45622)

### Why?

Small nit I noticed when configuring `ty` from Zed docs, ty should
always be stylized as lowercase.

See:
https://github.com/astral-sh/ty?tab=readme-ov-file#how-should-i-stylize-ty

Release Notes:

- N/A
8e825033f8Rob Hand committed on 1/2/2026, 6:06:15 AM· committed by GitHubparent872b2b3
2 files changedLine totals unavailable