ember-cli 3.28.0 on Node.js NPM

#9505 Pass realPath as root rather than the dirname for addonMainPath @brendenpalmer
#9507 Add a new config, ember-addon.projectRoot, to specify the location of the project @brendenpalmer
#9530 Drop Node 10 support @rwjblue
#9487 Add support for creating a single addon instance per bundle root (which enables dramatically reducing the total number of addon instances) @davecombs
#9524 Update CONTRIBUTING.md to reference cli.emberjs.com @loganrosen
#9533 Ensure package-info objects are stable when they represent the same addon @brendenpalmer
#9538 ensure backwards compatibility is maintained with packageRoot and root @brendenpalmer
#9539 avoid setting root as realPath from the package-info object @brendenpalmer
#9537 Implement LCA host/host addons logic in ember-cli @brendenpalmer
#9540 Use relative override paths in blueprint ESLint config @loganrosen
#9542 Add validation checks for addon instance bundle caching @brendenpalmer
#9543 Add ability to specify a custom ember-addon.perBundleAddonCacheUtil utility @brendenpalmer
#9562 Update addon-proxy to support Embroider @brendenpalmer
#9565 Drop Node 10 support in blueprint engine spec @elwayman02
#9568 [BUGFIX release] Skip babel for qunit with embroider @ctjhoa

Thank you to all who took the time to contribute!

ember-cli 3.28.0 Release 3.28.0 on Node.js NPM