Prettier automatically adds <> escapes around
invalid characters in links, as allowed by
CommonMark:
<https://spec.commonmark.org/0.31.2/#link-destination>.
This will come up in CatDog.md, where a Wikipedia
link uses ambiguous parentheses that must be
escaped like this. This commit adds support for
parsing these kinds of links. There is no
indication in the syntax tree on what kind of link
it originally was since this information doesn't
seem relevant to renderers.