docs: edit spelling on gradient documentation

[crgk]

I spotted some minor errors/typos in the docs for makeLinearGradient and makeRadialGradient. Here's a quick patch to fix.

Thanks for the project! I've really enjoyed using it.

[crgk]

Hmm, I'm surprised by how big the types.d.ts diff is. Maybe I shouldn't have regenerated that?

[jonobr1]

Yeah, sorry about that. The generation script for Types is out of sync with the types.d.ts file. If you don't mind rolling that back. I'd be happy to add your PR.

[crgk]

All set! Thanks for having a look.

[jonobr1]

Awesome, thank you!