Doxygen setup for contionuous documentation

Summary:

• Adds automatic doxygen documentation of libraries.
• Sets up various feature.
• Adds pipenv support.
• Adds script to document the Aircraft XML file.

added typedocumentation label

requested review from @sebastian.oberschwendtner

assigned to @sebastian.oberschwendtner

approved this merge request

mentioned in commit c6ae153e

merged