Proposal about wokflow for RegistratorServerless

[giordano]

Saving here some ideas suggested a few days ago in Slack:

• We install RegistratorServerless in General, with issues in a separate repository (GeneralRegistrationRequests?)
• Package dev installs in their repository RegisterAction or a new cool action which triggers registration whenever the version is bumped in Project.toml (the latter requires a bit of discipline like not bumping if you don't want to register yet, but it's very straightforward and would also be opt-in, so that's OK). These actions can be used only by users with write access to the repository
• These actions, with an appropriate token, will create an issue/comment on an issue in GeneralRegistrationRequests to trigger registration

Alternatively, package devs can not have any actions in their repository but they'll need to manually comment in the issue in GeneralRegistrationRequests