The primary difference between CKEditor custom config 8.x-2.x and 8.x-1.x is that custom configuration is now stored with the configuration of individual editors instead of being stored globally.
This is a release candidate for the next feature release of Drupal 8. Release candidates are not supported for production sites, but they are intended for widespread testing in preparation for the upcoming stable release. More information on release candidates.
This release fixes security vulnerabilities present in 8.7.0-beta2. Sites are urged to upgrade immediately after reading the security announcement and notes below:
You must add "enable-patching": true to your composer.json file so that we can patch the Payment module.
Additional instructions are in the documentation at https://performantlabs.gitbook.io/campaign-kit.