doc: Group options in pg_amcheck reference page

The previous arrangement was just one big list, and the internal order
was not all consistent either.  Now arrange the options by group and
sort them, the way it's already done in the --help output and one
other reference pages.  Also fix some ordering in the --help output.

src/bin/pg_amcheck/pg_amcheck.c

@@ -1187,11 +1187,11 @@ help(const char *progname)
 	printf(_("  -e, --echo                      show the commands being sent to the server\n"));
 	printf(_("  -j, --jobs=NUM                  use this many concurrent connections to the server\n"));
 	printf(_("  -q, --quiet                     don't write any messages\n"));
+	printf(_("  -P, --progress                  show progress information\n"));
 	printf(_("  -v, --verbose                   write a lot of output\n"));
 	printf(_("  -V, --version                   output version information, then exit\n"));
-	printf(_("  -P, --progress                  show progress information\n"));
-	printf(_("  -?, --help                      show this help, then exit\n"));
 	printf(_("      --install-missing           install missing extensions\n"));
+	printf(_("  -?, --help                      show this help, then exit\n"));
 
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 	printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);