Clarify that link text may contain a line ending

[ongardie]

I was looking through the spec to try to make sure that link text is allowed to have a line break. I think this is the case, but I couldn't pinpoint where in the spec it's stated. It'd be nice to include test cases showing that link text may contain a single line ending.

This is obviously OK:

[foo1 bar](https://example.org)

This one should be OK:

[foo2
bar](https://example.org)

This one is not OK:

[foo3

bar](https://example.org)

(VS Codium with rust-analyzer doesn't highlight such links in Rust doc comments, and I'm trying to track down where this goes wrong.)

[jgm]

Spec says that link text contains "a sequence of zero or more inline elements."

Since soft and hard line breaks are both inline elements, they are allowed.

In your "not OK" example, the blank line splits the content into two separate paragraphs. General rule stated in spec: block parsing takes precedence over inline parsing.

[ongardie]

Ah, thank you for the explanation @jgm and for all your work on this spec. Sorry for the noise here. I still think a test case could help ensure compatibility, but feel free to close this if you think it's sufficiently covered by blanket rules.