Docs: not using shouty caps in unitd.8.

There was a recent unanimous agreement by maintainers of groff, mandoc,
the Linux man-pages, and other relevant programmers, that manual pages
should not use uppercase unnecessarily.  Use of uppercase in the title
and in the section's titles dates from before one could use bold,
italics, and other such formatting, so that it was the way of giving
more importance to certain parts of a page.  Nowadays, we use bold, so
uppercase is unnecessary.

Moreover, using uppercase in the title is bad, since it removes
information.  If we keep the exact casing used in the program (or
function) name, we provide more information.  And anyway, if users want
to read in uppercase, they can program certain mdoc(7) or man(7) macros
to transform their arguments into uppercase.  This could be done via
</etc/groff/mdoc.local> and </etc/groff/man.local>.

There's a plan of transforming OpenBSD pages and the Linux man-pages to
stop using uppercase.  Other projects may join.  That will likely happen
in the following months.  Let's align with this.

Reviewed-by: Artem Konev <a.konev@f5.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>

docs/man/man8/unitd.8.in

@@ -1,12 +1,12 @@
 .\" (C) 2017-2021, NGINX, Inc.
 .\"
 .Dd March 16, 2021
-.Dt UNITD 8
+.Dt unitd 8
 .Os
-.Sh NAME
+.Sh Name
 .Nm unitd
 .Nd "runs the NGINX Unit daemon"
-.Sh SYNOPSIS
+.Sh Synopsis
 .Nm
 .Op Fl Fl no-daemon
 .Op Fl Fl control Ar socket
@@ -18,14 +18,14 @@
 .Op Fl Fl state Ar directory
 .Nm
 .Op Fl h | Fl Fl help | Fl Fl version
-.Sh DESCRIPTION
+.Sh Description
 NGINX Unit is a polyglot app server, a reverse proxy, and a static file server
 for UNIX-like systems.
 It was built by
 .Xr nginx 8
 team members from
 scratch to be highly efficient and fully configurable at runtime.
-.Sh OPTIONS
+.Sh Options
 .Bl -tag -width indent
 .It Fl h , Fl Fl help
 Displays a summary of Unit's command-line options and their
@@ -52,23 +52,23 @@ Overrides the pathname for the PID file of Unit's main process.
 .It Fl Fl state Ar directory
 Overrides the directory path for Unit's state storage.
 .El
-.Sh EXIT STATUS
+.Sh Exit status
 Exit status is 0 on success, or 1 if the daemon encounters an error.
-.Sh FILES
+.Sh Files
 .Bl -tag -width indent
 .It Pa %%PID_PATH%%
 The PID file of Unit's main process.
 .It Pa %%ERROR_LOG_PATH%%
 A general-purpose log for diagnostics and troubleshooting.
 .El
-.Sh SOCKETS
+.Sh Sockets
 .Bl -tag -width indent
 .It Pa %%SOCKET_PATH%%
 The socket address of Unit's control API.
 .El
-.Sh AUTHORS
+.Sh Authors
 (C) 2017-2021, NGINX, Inc.
-.Sh SEE ALSO
+.Sh See also
 .Pp
 Website:
 .Pa https://unit.nginx.org