Rename pixelRatio functions to pixelScale

[joan-teriihoania]

Change to the theme's customization documentation where the pixelRatio and pixelRatioSelect functions are not exported by the implementation (see #45 for more details), but pixelScale and pixelScaleSelect are.

This PR is based on the assumptions

• that pixelScale and pixelRatio have the same behaviour, side-effects, and outputs, then this could be a simple case of documentation-implementation reconciliation.
• that the complexity of renaming these functions across multiple code sections and packages is far greater and shadows the effort required compared to a simple documentation change.

---

Closes #45

[vercel]

@joan-teriihoania is attempting to deploy a commit to the nativewind Team on Vercel.

A member of the Team first needs to authorize it.

[danstepanov]

@joan-teriihoania is there a reason that this is a draft PR?

[joan-teriihoania]

@danstepanov I wasn't sure if this issue should be resolved by a PR on the website, or on the package itself (see assumptions in description). Though, in retrospect, the draft isn't really warranted. I've marked this to ready for review.