docs: release notes for the v12.2.6 release
docs: release notes for the v12.2.6 release

clydin/angular-cli,Brocco/angular-cli,catull/angular-cli,angular/angular-cli,geofffilippi/angular-cli,catull/angular-cli,Brocco/angular-cli,geofffilippi/angular-cli,geofffilippi/angular-cli,geofffilippi/angular-cli,Brocco/angular-cli,angular/angular-cli,Brocco/angular-cli,clydin/angular-cli,angular/angular-cli,angular/angular-cli,Brocco/angular-cli,clydin/angular-cli,catull/angular-cli,clydin/angular-cli,catull/angular-cli