Occultations and New Frames

• Added occultations and shadows]
• Introduced True-of-Date and J2000 Equatorial frames
• Initialised the DiscreteTimeData interpolator
• Migrate Documentation to MyST Markdown

Version 0.1

Initial release with a limited but useful set of functionalities.

• Added TleStorage and TleTimeSeries classes to load and filter multiple TLEs
• Improved units handling of TLEs
• Moved analyses to a dedicated project called SatMAD Applications,
  available at Github https://github.com/egemenimre/satmad_applications (for Jupyter notebooks)
  and in plain document format https://satmad-applications.readthedocs.io/.

version 0.0.7

Bumped version to 0.0.7