Update types to use generics & add a TS test for react-redux

[kale-stew]

Description

Rel: #69

This PR introduces a test for react-redux's useSelector hook to access state. Ideally, we should also confirm the # of overlapping values to make sure we're using the hook as expected, but I didn't want to get too into the weeds of wrapping another test around this one.

Would appreciate feedback / input on how I can enhance this test.

Checklist:

• All tests are passing
• Type definitions, if updated, pass both test-ts-defs and test-ts-usage
• Benchmark performance has not significantly decreased
• Bundle size has not been significantly impacted
• The bundle size badge has been updated to reflect the new size N/A, still at 369

[chrisbolin]

our goal here is to have a failing test, just like #61

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (master@e01e975). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #80   +/-   ##
=========================================
  Coverage          ?   98.21%           
=========================================
  Files             ?        1           
  Lines             ?       56           
  Branches          ?        0           
=========================================
  Hits              ?       55           
  Misses            ?        1           
  Partials          ?        0           

Impacted Files	Coverage Δ
index.js	98.21% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e01e975...4e761cd. Read the comment docs.

[chrisbolin]

just one thing i missed in my previous review. Also, since i went ahead and corrected the types, we should probably include that in the title of the PR, so we don't forget that we changed the types - a big deal, as it changes the library's API.