Housekeeping

• Added additional calls to Methods.try_copy() where it is sensible to copy method params before mutating them, or in similar circumstances
  (from a user perspective, this means that there should be no mutability gotchas when using this package - any params passed in will have a working copy created to mutate internally, and any return values will also be copies themselves)
• Renamed positional params from method to method_name in Listeners for clarity
• Minor improvements to error messages
• Fixes to type hints
• Improvements to docstrings
• Updated readme
• Updated dependency

This release features minor breaking changes in the form of renamed positional params.