feat: stable mapSliceZone (previously unstable_mapSliceZone)

[angeloashmore]

Types of changes

• Chore (a non-breaking change which is related to package maintenance)
• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

This PR promotes mapSliceZone to a stable helper. unstable_mapSliceZone should no longer be used.

It also fixes some types for better autocompletion and type checking.

Migration guide

Replace all unstable_mapSliceZone imports and uses with mapSliceZone.

- import { createClient, unstable_mapSliceZone } from "@prismicio/client";
+ import { createClient, mapSliceZone } from "@prismicio/client";

  const client = createClient("example-prismic-repo");
  const page = await client.getByUID("page", "home");

- const mappedSliceZone = unstable_mapSliceZone(
+ const mappedSliceZone = mapSliceZone(
    page.data.slices,
    {
      image: ({ slice }) => ({ url: slice.primary.image.url }),
    }
  )

Checklist:

• My change requires an update to the official documentation.
• All TSDoc comments are up-to-date and new ones have been added where necessary.
• All new and existing tests are passing.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.97%. Comparing base (bd55071) to head (b54f393).

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #336   +/-   ##
=======================================
  Coverage   99.97%   99.97%           
=======================================
  Files          61       61           
  Lines        6885     6905   +20     
  Branches      381      381           
=======================================
+ Hits         6883     6903   +20     
  Misses          2        2           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.