Add mandoc-manpage for link(1)

and mark it as finished in the README.

link.1

@@ -1,14 +1,18 @@
-.TH LN 1 sbase\-VERSION
-.SH NAME
-link \- create a hard link by calling the link function
-.SH SYNOPSIS
-.B link
-.I target
-.I linkname
-.P
-.SH DESCRIPTION
-.B link
-creates a hard link to a given file, with the given name.
-.SH SEE ALSO
-.IR ln (1),
-.IR link (2)
+.Dd January 25, 2015
+.Dt LINK 1 sbase\-VERSION
+.Sh NAME
+.Nm link
+.Ar target
+.Ar name
+.Sh DESCRIPTION
+.Nm
+creates a hard link
+.Ar name
+to
+.Ar target .
+.Sh STANDARDS
+The
+.Nm
+utility is compliant with the
+.St -p1003.1-2008
+specification.