`better-macro` has deliberate RCE to prove a point

better-macro is a fake crate which is
“Proving A Point” that proc-macros can run arbitrary code. This is not a particularly
novel or interesting observation.

It currently opens https://github.com/raycar5/better-macro/blob/master/doc/hi.md
which doesn’t appear to have any malicious content, but there’s no guarantee that
will remain the case.

This crate has no useful functionality, and should not be used.