add notebook examples and adapted documentation

...otebooks/Calibration of a standard resistor example.ipynb

code/Notebooks/Generic Example - Different Cases.ipynb

code/Notebooks/Linear mass calibration example.ipynb

...inear mass calibration example with conjugate prior.ipynb

...ass example with noninformative data variance prior.ipynb

code/Notebooks/data/mass_dem/nu_10_k0_1/result.dat

code/Notebooks/data/mass_dem/nu_10_k0_10/result.dat

code/Notebooks/data/mass_dem/nu_10_k0_3/result.dat

code/Notebooks/data/mass_dem/nu_30_k0_1/result.dat

code/Notebooks/data/mass_dem/nu_3_k0_10/result.dat

code/Notebooks/data/mass_dem/nu_3_k0_3/result.dat

code/docs/Code.rst

code/docs/Examples.rst

code/docs/ex_generic.nblink

code/docs/ex_linear_mass.nblink

code/docs/ex_nonlinear_mass_1.nblink

code/docs/ex_nonlinear_mass_2.nblink

code/docs/ex_resistor.nblink

code/docs/modules.rst

code/example_generic.py