[DOC] Remove pagefront from plugin packs
[DOC] Remove pagefront from plugin packs

Just cleaning up the docs to no longer reference a service that seemingly doesn't exist anymore. 

This service's homepage - https://www.pagefronthq.com/ - displays nothing, so it seems they're no longer around.  

I found this while searching for CloudFront-related items by searching for "front" on the page, so figured I'd take this opportunity to clean up the docs a little ☺️
ember-cli-deploy/ember-cli-deploy,ember-cli/ember-cli-deploy,ember-cli/ember-cli-deploy,ember-cli/ember-cli-deploy,ember-cli-deploy/ember-cli-deploy,ember-cli-deploy/ember-cli-deploy