pmpm: Python manual package manager v0.2.0 release

• v0.2.0: First PyPI release.
  • features:
    • support installing packages from another git branch / tag, such as toast=toast3.
    • pmpm cli & flags
      • replace *_install_from_file by --file flag
      • add --pip-dependencies
      • add --install-ipykernel
      • add --arch
      • add --tune
      • remove nomkl
    • less automatic stateful settings such as detecting Intel CPU.
    • read from / write to YAML formats rather than JSON.
    • make conda-activation works more reliably by running conda run instead.
    • add pmpm_env_variant_generator
    • refactor how defaults work.
    • drop Python 3.8-3.9, add Python 3.12.
    • remove Windows support.
  • maintenance:
    • improve type-hints.
    • refactor pmpm.util
    • remove pmpm.templates
    • add documentation on GitHub Pages and Read the Docs.
    • improve integration tests.
    • migrate from bump2version to bump-my-version