v2.0.0

• Performance improved by 10-30%
• New features
  • SCF class
  • Domains
  • LibXC interface
  • Examples
  • CG minimizer
  • Simplify and optimize operators
• Updated docs
  • New theme with dark mode
  • Add examples, changelog, and license pages
  • Add dev information
  • Enable compression
• Coding style
  • Improve comments and references
  • A lot of refactoring and renaming
  • Google style docstrings
  • Use loggers
  • Unify coding style
  • Remove legacy code
• Miscellaneous
  • Improved setup.py
  • More tests
  • Improve readability
  • Fix various bugs