Clean up, simplify, test, cite

• Removed Planck LevelS files
  • Replaced by custom (simpler) classes/functions for binary file I/O and parameter file reading
• Added Catch2 for testing
  • Added tests for binary file I/O and parameter file reading
• Added CITATION.cff file for computer readable citation information

Version 0.0.1: First public release.

v0.0.1

Version 0.0.1: First public release.