rename README -> README.md; uniform subdirectory name Python/, not

.../simulation/ex06_Reflectometry/BasicSpecularSimulation.py

...on/simulation/ex06_Reflectometry/BeamAngularDivergence.py

...ython/simulation/ex06_Reflectometry/BeamFullDivergence.py

...thon/simulation/ex06_Reflectometry/FootprintCorrection.py

...s/Python/simulation/ex06_Reflectometry/MaterialProfile.py

...lation/ex06_Reflectometry/MaterialProfileWithParticles.py

...thon/simulation/ex06_Reflectometry/PolarizedNoAnalyzer.py

...x06_Reflectometry/PolarizedNonperfectAnalyzerPolarizer.py

...n/simulation/ex06_Reflectometry/PolarizedSpinAsymmetry.py

...imulation/ex06_Reflectometry/PolarizedSpinAsymmetryFit.py

...Python/simulation/ex06_Reflectometry/PolarizedSpinFlip.py

...es/Python/simulation/ex06_Reflectometry/RoughnessModel.py

...ion/ex06_Reflectometry/SpecularSimulationWithRoughness.py

...ython/simulation/ex06_Reflectometry/TOFRWithResolution.py

...imulation/ex06_Reflectometry/TimeOfFlightReflectometry.py

...ulation/ex06_Reflectometry/genx_angular_divergence.dat.gz

...mulation/ex07_Miscellaneous/AccessingSimulationResults.py

...hon/simulation/ex07_Miscellaneous/AxesInDifferentUnits.py

...on/simulation/ex07_Miscellaneous/BoxesWithSpecularPeak.py

.../simulation/ex07_Miscellaneous/CylindersInAverageLayer.py