Add mandoc-manpage for rmdir(1)

and mark it as finished in README.

README

@@ -56,7 +56,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
 =  readlink        non-posix                       none
 =* renice          yes                             none
 =* rm              yes                             (-i)
-=  rmdir           no                              -p
+=* rmdir           yes                             none
 =  setsid          non-posix                       none
 =  sleep           yes                             none
    sort            no                              -m, -o, -d, -f, -i

rmdir.1

@@ -1,25 +1,32 @@
-.TH RMDIR  1 sbase\-VERSION
-.SH NAME
-rmdir \- remove a directory
-.SH SYNOPSIS
-.B rmdir
-.I directory...
-.SH DESCRIPTION
-.B rmdir
-attempts to remove all non-full directories specified
-by
-.IR directory.
-.SH BUGS
-Subdirectories are removed in the order specified, so
-.nf
-	rmdir foo/bar foo
-.fi
-will be successful, but
-.nf
-	rmdir foo foo/bar
-.fi
-will only succeed in removing
-.BR foo/bar.
-
-.SH SEE ALSO
-.IR rm (1) rmdir (2) unlink (1) unlink (2)
+.Dd January 30, 2015
+.Dt RMDIR 1 sbase\-VERSION
+.Sh NAME
+.Nm rmdir
+.Nd remove directories
+.Sh SYNOPSIS
+.Nm rmdir
+.Op Fl p
+.Ar directory ...
+.Sh DESCRIPTION
+.Nm
+removes each empty
+.Ar directory .
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl p
+Remove
+.Ar directory
+and its parents in the pathname
+.Ar directory .
+.El
+.Sh SEE ALSO
+.Xr rm 1 ,
+.Xr rmdir 2 ,
+.Xr unlink 1 ,
+.Xr unlink 2
+.Sh STANDARDS
+The
+.Nm
+utility is compliant with the
+.St -p1003.1-2008
+specification.