doc: clarify AppendResidue can take a residue handle

modules/mol/base/doc/editors.rst

@@ -69,19 +69,24 @@ The basic functionality of editors is implemented in the EditorBase class.
      :returns:          :class:`ChainHandle`
 
   .. method:: AppendResidue(chain, residue_name, [res_num])
-              AppendResidue(chain, residue_name, deep=False)
+              AppendResidue(chain, residue, deep=False)
   
-     Append residue to the end of the chain. If res_num is not given, the
-     residue number will be set to the residue number of the last added residue
-     plus one. The insertion code is the same.
+     Append residue to the end of the chain.
 
-     By default, atoms and bonds are not added. If deep is `True`, atoms (but
-     not bonds) are added to the new residue, including alternative atoms.
+     If res_num is not given, the residue number will be set to the residue
+     number of the last added residue plus one. The insertion code is the same.
+
+     It is possible to give a residue handle as second argument, instead of a
+     residue name. By default, atoms and bonds are not added. If deep is
+     `True`, atoms (but not bonds) are added to the new residue, including
+     alternative atoms.
 
      :param chain: Must be a valid chain
      :type  chain: :class:`ChainHandle`
      :param residue_name: 3-letter-code of the residue, e.g. ``GLY``.
      :type  residue_name: :class:`string`
+     :param residue: A residue handle to copy
+     :type  residue: :class:`ResidueHandle`
      :param deep: If set to true, insert atoms as well.
      :type  deep: :class:`bool`
      :returns:     :class:`ResidueHandle`