Add some doxygen documentation

dune/fufem/assemblers/localassemblers/generalizedboundarymassassembler.hh

@@ -19,6 +19,9 @@
 /** \brief Local Robin boundary assembler
  * 
  * \tparam GridType The grid we are assembling for
+ * \tparam The trial local finite element type
+ * \tparam The ansatz local finite element type
+ * \tparam The function for evaluating the coefficient
  * \tparam T Type used for the set of dofs at one node
  */
 template <class GridType, class BoundaryPatchType, class TrialLocalFE, class AnsatzLocalFE, class Function, class T=Dune::FieldMatrix<typename GridType::ctype,1,1>>