15.4.20220930 (tracked in bsc#933411)
- Added note about SUSEConnect tracking (jsc#SLE-23312)
- Updated doc-url to 15 SP4 (bsc#1198573)
- Updated install info (bsc#1198573)
- Added disable C-states in what's new section (jsc#SLE-24923)


15.4.20220426 (tracked in bsc#933411)
  - Initial release of 15.4 release notes (bsc#1198573)

15.3.20210914 (tracked in bsc#933411)
  - Initial release of 15.3 release notes
