Add user friendly first party ActivityPub handle support

[Dark_Arc]

Firefox has long supported mailto://[email protected] as a way to handle sending an email to the designated person. To make federation of social media more mainstream, democratized, and user friendly, Firefox should support an activitypub://[email protected] URL protocol.

https://github.com/mastodon/mastodon/issues/14187

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[ZackDunn]

`[email protected]` is not an ActivityPub id and has no meaning to ActivityPub. An ActivityPub id is actually just a URI. At-handles are a convenience Mastodon borrowed from Twitter for referencing users and they require a separate protocol, WebFinger, which not all AP implementations will support.