User's Guide: reverse flags not listed in html

From: #21314 (comment 419078)

See the source code for the documentation fo the -fprof-auto-exported flag.

.. ghc-flag:: -fprof-auto-exported
    :shortdesc: Auto-add ``SCC``\\ s to all exported bindings not marked :pragma:`INLINE`
    :type: dynamic
    :reverse: -fno-prof-auto

Note that the reverse flag is not rendered here: https://downloads.haskell.org/ghc/latest/docs/html/users_guide/profiling.html#ghc-flag--fprof-auto-exported

It is rendered in the pdf.

I've not investigated whether any reverse flags are rendered in html.

cc @AndreasK