add weak fem-bem coupling example

...BEM_coupling/pybind11/include/pybind11/detail/internals.h

...EM_BEM_coupling/pybind11/include/pybind11/detail/typeid.h

...l/weak_FEM_BEM_coupling/pybind11/include/pybind11/eigen.h

...l/weak_FEM_BEM_coupling/pybind11/include/pybind11/embed.h

...ll/weak_FEM_BEM_coupling/pybind11/include/pybind11/eval.h

...k_FEM_BEM_coupling/pybind11/include/pybind11/functional.h

...eak_FEM_BEM_coupling/pybind11/include/pybind11/iostream.h

...l/weak_FEM_BEM_coupling/pybind11/include/pybind11/numpy.h

...ak_FEM_BEM_coupling/pybind11/include/pybind11/operators.h

...weak_FEM_BEM_coupling/pybind11/include/pybind11/options.h

...eak_FEM_BEM_coupling/pybind11/include/pybind11/pybind11.h

...weak_FEM_BEM_coupling/pybind11/include/pybind11/pytypes.h

...ell/weak_FEM_BEM_coupling/pybind11/include/pybind11/stl.h

...eak_FEM_BEM_coupling/pybind11/include/pybind11/stl_bind.h

...well/weak_FEM_BEM_coupling/pybind11/tools/FindCatch.cmake

...ell/weak_FEM_BEM_coupling/pybind11/tools/FindEigen3.cmake

...k_FEM_BEM_coupling/pybind11/tools/FindPythonLibsNew.cmake

...xwell/weak_FEM_BEM_coupling/pybind11/tools/check-style.sh

...s/maxwell/weak_FEM_BEM_coupling/pybind11/tools/libsize.py

...les/maxwell/weak_FEM_BEM_coupling/pybind11/tools/mkdoc.py