Some broken links are not reported as such

[dbuenzli]

The first fwo reference to Format on this page in the preamble:

https://b0-system.github.io/odig/dev/fmt/Fmt/index.html

are not reported as broken while further refs to value of Format down are. The corresponding ocamldoc markup is here:

https://github.com/dbuenzli/fmt/blob/d1c1bb26e00f22c160e6cc5d6b6376bce8426115/src/fmt.mli#L13-L15