Swap lerna with release-it

[anselmbradford]

Changes

• Swap lerna with release-it.
• Add auto-changelog and a changelog handlebars template for formatting the changelog.
• Rename the root CHANGELOG.md to HISTORY.md
• Add a CHANGELOG.md to the cfpb-design-system package, with version v3+.

Testing

1. In package.json, add --dry-run to the release script and then run yarn release and it should allow you to select the version to release.

Notes

• I'm ignoring the merge title pattern that decap adds, to avoid putting decap edits in the package changelog. I don't love depending on the merge title, but that seemed to be the only way to do it with auto-changelog.
• I wasn't getting the GitHub release notes to populate correctly, but I wasn't sure if this was because it was a dry run. We'll likely want to do some adjustments after doing some live releases.

[netlify]

✅ Thanks for the improvements! Browse a preview of your changes using the link below.

Name	Link
🔨 Latest commit	3eb955a
🔍 Latest deploy log	https://app.netlify.com/sites/cfpb-design-system/deploys/66f57cf35de3d300088c42bd
😎 Deploy Preview	https://deploy-preview-2058--cfpb-design-system.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[contolini]

I'm excited to try this!