Add some tutorial on basic OpenSWATH chromatogram algorithms

[timosachsenberg]

OpenSWATH provides a lot of low-level but highly useful chromatogram processing algorithms, but they are currently very hidden from python users.
It would be great to add those to the pyopenms documentation as a new menu entry.

e.g.:

• PeakIntegrator
• PeakPickerMRM
• ... TODO add more