manuals: Fix more Fx and nearby mechanical typos

Fix compiler warnings related to the Fx macro, as well as all other
mechanical typos that were visible within one screenful of them. These
cause rendering glitches on various toolchains with various of the five
and a half decades of rich output formats and tooling manpages scale to.

The *x macro set specifies operating systems. These macros take the rest
of the line as an argument. Sometimes, a space was not used to separate
the argument of Fx and the trailing period. Others had other parts of
the sentence supplied as an argument to Fx.

While here, fix the other mechanical typos visible on those specific
screenfulls. Correct section typo AUTHOR to AUTHORS, markup utilities
with Sy, and apply line break after the end of a sentence.

PR: 297248
MFC after: 3 days
Reported by: wosch (are you sure that's all of the broken Fx'es?)
Fixes: ff2bc641599a ("Fix Fx and nearby mechanical typos")
Fixes: d790b16bbf0c ("add man pages for stdbit functions")
Fixes: 6c57e368eb17 ("implement C23 memalignment()")
Fixes: b06338167d64 ("ROUTE_MPATH and FIB_ALGO")
Fixes: 7e1affa242ca ("revise divert-to and divert-reply")