docs/40196: man find does not describe -follow

[Gary W. Swearingen]

des at des.no (Dag-Erling Smørgrav) writes:

> If you insist on documenting -follow, make sure to
>
>  - document it in the correct section (PRIMARIES, not DESCRIPTION)

>From the mdoc(7) manpage's list of section descriptions:

     .Sh COMPATIBILITY  Known compatibility issues (e.g. deprecated options or
                        parameters) should be listed here.