[CI:DOCS] Restore man page cross-checker

Somewhere in the CIv2 migration we lost the man page vs --help
cross-checker. Add it back, by adding it into the man-page-check
Makefile target; this is part of 'make validate', which is run
in CI even on CI:DOCS PRs.

As happens when CI doesn't run, things broke. Man pages got out
of sync with --help. This PR:

 1) Fixes hack/xref-helpmsgs-manpages to deal with the new
    "Options" (instead of "Flags") form of podman help. #8034
    did part of that, but one of my review comments was
    accidentally left out.

 2) Fixes hack/xref-helpmsgs-manpages to deal with the new
    option syntax in man pages, post- #8292, in which each
    option is preceded by four hashes so as to make them
    HTML <h4> elements with named anchors.

 3) Fixes man pages that #8292 accidentally missed.

 4) Adds man page entries for two flags that got added
    to podman but not documented (pod create --network-alias,
    play kube --log-driver)

Fixes: #8296

Signed-off-by: Ed Santiago <santiago@redhat.com>

docs/source/markdown/podman-volume-prune.1.md

@@ -14,7 +14,7 @@ unused volumes. To bypass the confirmation, use the **--force** flag.
 
 ## OPTIONS
 
-**-f**, **--force**
+#### **-f**, **--force**
 
 Do not prompt for confirmation.