ci: configure renovate to manage GitHub workflow updates
ci: configure renovate to manage GitHub workflow updates

Update renovate config to allow GitHub workflow updates

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