LP-11431.7: Add changeset .md file (#187)
LP-11431.7: Add changeset .md file (#187)

## Summary:
Landing this PR will trigger the changesets bot to create a "Version Packages" PR that we can then use to publish a '@khanacademy/kas' package to NPM.

Issue: LP-11431

## Test plan:
- n/a

Author: kevinbarabash

Reviewers: jeremywiebe

Required Reviewers:

Approved By: jeremywiebe

Checks: ⌛ Test Coverage (ubuntu-latest, 16.x), ⌛ Check builds for changes in size (ubuntu-latest, 16.x), ✅ Lint, Flow, and Test (ubuntu-latest, 16.x), ✅ Extract i18n strings (ubuntu-latest, 16.x)

Pull Request URL: https://github.com/Khan/perseus/pull/187
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