4.1.0

• Add mean pooling
• Make everything hashable
• Add additional tests

• Fix bug, add test by @stephantul in #27
• 28 switch to ruff by @stephantul in #29
• 25 switch to pyprojecttoml by @stephantul in #31
• 30 move from string to hashable by @stephantul in #32
• 34 add pooling functions with safeguard by @stephantul in #35
• Bump version, add examples to README by @stephantul in #37