Support `@[email protected]` markdown

[Sjmarf]

Requirements

• [X] This is a feature request and not a bug report. Otherwise, please create a new bug report instead.
• [X] Please check to see if this request (or a similar one) already exists.
• [X] It's a single feature. Please don't request multiple features in one issue.

Describe the feature you'd like

Lemmy-ui renders [email protected] as a community link. It does not render @[email protected] as a user link. Instead, when you start typing a user link in that format, it lets you search Lemmy users and inserts a markdown link like so:

[@[email protected]](https://example.com/u/user)

Is there a reason why it's done this way? Supporting @[email protected] directly as done with community links seems simpler to me.

Side note: is the markdown documentation found here for Lemmy as a whole or just for Lemmy-ui? It seems to be missing a few features that Lemmy-ui supports (strikethrough, tables, community links and footnote references). This makes it unclear which features I need to be supporting as a client developer. If it is indeed incomplete, I’d be happy to expand on it :)