fixed minor typo in each loop animation error

[mkhan45]

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• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with npm test and lint the project with npm run lint

This error message has a typo:
An element that use the animate directive must be the immediate child of a keyed each block

It should instead be
An element that uses the animate directive must be the immediate child of a keyed each block

or maybe
Elements that use the animate directive must be the immediate child of a keyed each block.

I decided on the former.

I'm not sure if this is worth the PR but it was bugging me