[Bug libstdc++/96995] The link to std API documentation is unversioned

[giecrilj at stegny dot 2a.pl]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96995

--- Comment #6 from Christopher Yeleighton <giecrilj at stegny dot 2a.pl> ---
Why wouldn’t locally installed documentation have the API book at the same
relative location?