Mark is a tool which detects duplicate, missing and unused references in markdown files.
go get github.com/lorenzo-stoakes/mark/...
$ mark <--fix> [markdown files...]
The tool outputs duplicates/missing references if they exist, otherwise it outputs nothing.
If any of the specified files have duplicate or missing entries, or if an error occurs, the tool exits with status code 1.
If the --fix flag is specified, then all unused and duplicate references will
be removed.