[styleguide] Use Turborepo and Changesets, remove Lerna

[jonsamp]

Why

Since Lerna is now no longer maintained, I am transferring our styleguide repos to use turborepo and changesets to build and release our packages.

I added directions on how to get started with these new commands in the README.md, but they are more or less drop-in replacements for Lerna.

Test plan

Make sure that the instructions in the readme make sense, and that you can run yarn, then yarn build successfully. Running yarn build more than once should be ">>> FULL TURBO", since turborepo caches the build results and only repeats them when changes are present.

After building the repo, you should be able to run yarn create:release, which should ask you some questions, then create a file. Then running yarn version should apply the version to the appropriate packages. Finally, yarn publish should run npm publish and publish the packages.

[Simek]

LGTM, I have tested the refactor locally and have no issues with build or dev scripts.

Also publish questionnaire seems to function as expected, great work Jon! 🙏