create sphinx docu

Setup sphinx to create automated documentation during CI

• setup sphinx
• add shell script for CI
• run CI and check if it works
• update docstrings in all modules
  • configuration
    • init
    • join_settings
    • path_config
  • data_handling
    • init
    • bootstraps
    • data_distributor
    • data_generator
    • data_preparation
  • helpers
    • init
    • datastore
    • helpers
    • join
    • logger
    • statistics
    • testing
    • time_tracking
  • model_modules
    • init
    • advanced_paddings
    • flatten
    • inception_model
    • keras_extension
    • linear_model
    • loss
    • model_class
  • plotting
    • init
    • postprocessing_plotting
    • training_monitoring
  • run_modules
    • init
    • experiment_setup
    • model_setup
    • post_processing
    • pre_processing
    • run_environment
    • training
  • init
• add general remarks in .rst or .md files
• create install instructions
• update missing docs:
  • model_modules/flatten
  • model_modules/inception_model
  • plotting/postpricessing_plotting: conditional quantiles