Correctly match `<name@domain.extension>` (email links)

Should match `-#` elements (aka captions) as a new node type.

For example:
```
Foo
<bar@baz.qux>
```
Is rendered as:

![Image](https://github.com/user-attachments/assets/676f25cb-d19a-4a49-a2f1-58c2e37b506f)
