Remaining todos here #1568

(most of this is documentation tho, and non-breaking)

Keeping track of changes here for the changelog, tho it does seem like release-it is set up, so this'll all probably be automatic:

Breaking

• Use the current Node LTS #1570

Enhancements

• Loosen version check against ember-cli-babel #1569
• Adding note to testing.md about qunit-dom #1562
• docs: Reference Glint in docs #1554
• Update getOwner example #1546

Fixes

• fix: typo in code example in components.md #1560
• Fix ModelRegistry declaration example #1563
• chore: Fix spelling mistake #1538

Dependencies

• chore(deps): bump decode-uri-component from 0.2.0 to 0.2.2 #1542
• Remove deprecated @types/ember__test-helpers from blueprint #1545