Add release automation setup.

[rwjblue]

This leverages a few external packages to make publishing nice and simple:

• release-it - Responsible for handling the main release process.
• release-it-lerna-changelog Responsible for building up a nice changelog (based on PRs merged, their labels and PR titles), then launching $EDITOR to allow hand tweaking of that changelog.
• release-it-yarn-workspaces Responsible for looping through packages, updating the versions (and dependency versions), and calling npm publish on each.

The RELEASE.md file here should describe the process in detail, but the highlevel process is:

• As you review and merge PRs, label them and update their titles to be something that is "changelog ready"
• When you are ready to release, run npx release-it
• Follow prompts
• Review changelog, and tweak as needed

Once the release-it process completes, the following will have been done:

• All version fields will be updated to the new version
• All related dependencies/devDependencies/peerDependencies will have
  their versions updated (to match the newly selected version)
• A CHANGELOG.md entry will have been created
• All packages/* will be published to npm
• A new GitHub Release will be published
• The branch and tag will be pushed

🎉

Fixes #585

[rwjblue]

This configuration is the only real difference from npx create-rwjblue-release-it-setup. It is specifically needed because we don't "just" want to use the workspaces array directly (since we don't want to publish test-packages/*).

[rwjblue]

For context, right now the generated CHAGNELOG.md entry for the changes queued up on master is:

---

Unreleased (2021-03-04)

🚀 Enhancement

• core
  • #705 Avoid patching the template compiler on Ember 3.26. (@rwjblue)
  • #700 TemplateCompiler fixes / improvements (avoid monkey patch for Ember 3.27+) (@rwjblue)
• macros
  • #694 Run importSync transform later, so ember-auto-import can support importSync (@simonihmig)

🐛 Bug Fix

• compat
  • #674 adjust paths seen by css preprocessors (@ef4)
  • #702 Handle case where node_modules are symlinked (@thoov)
  • #690 Exclude 'babel-plugin-compact-reexports' during Stage 1 build (@charlespierce)
  • #687 Strip main field from v1 addons' package.json once they are rewritten as V2 (@ef4)
• compat, core
  • #709 Fix the path to the on-disk styles file for in-repo engines (@charlespierce)
• core
  • #686 Prevent accidental duplication of babel plugin during rebuilds (@ef4)

🏠 Internal

• core, macros
  • #707 Fixup types for newer @babel/types. (@rwjblue)
• Other
  • #704 Avoid running CI jobs on both push and pull_request events. (@rwjblue)
  • #697 Refactor suite-setup-util to avoid knock on errors. (@rwjblue)
• router, util
  • #703 Add 3.20 and 3.24 to list of matrix tests. (@rwjblue)

Committers: 5

• Charles Pierce (@charlespierce)
• Edward Faulkner (@ef4)
• Robert Jackson (@rwjblue)
• Simon Ihmig (@simonihmig)
• Travis Hoover (@thoov)

[ef4]

Thanks, looks great.

[ef4]

I tried running this for the first time, and it died at the point where it started trying to publish the npm packages.

? Preparing to publish:
    @embroider/babel-loader-7
    @embroider/compat
    @embroider/core
    @embroider/hbs-loader
    @embroider/macros
    @embroider/router
    @embroider/shared-internals
    @embroider/test-setup
    @embroider/util
    @embroider/webpack
  Publish to npm: Yes
ERROR npm ERR! code 128
npm ERR! command failed
npm ERR! command git ls-remote ssh://git@github.com/packages/babel-loader-7.git
npm ERR! ERROR: Repository not found.
npm ERR! fatal: Could not read from remote repository.
npm ERR!
npm ERR! Please make sure you have the correct access rights
npm ERR! and the repository exists.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/edward/.npm/_logs/2021-03-31T00_06_31_201Z-debug.log

Is there something weird about my environment?

(I finished the release by publishing the packages manually, everything else looks like it happened successfully.)