Bump @khanacademy/simple-markdown from 0.8.5 to 0.8.6 (#992)

Bump @khanacademy/simple-markdown from 0.8.5 to 0.8.6 (#992)

Bumps [@khanacademy/simple-markdown](https://github.com/Khan/simple-markdown) from 0.8.5 to 0.8.6.
- [Release notes](https://github.com/Khan/simple-markdown/releases)
- [Commits](https://github.com/Khan/simple-markdown/commits)

---
updated-dependencies:
- dependency-name: "@khanacademy/simple-markdown"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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