- Remove support for custom player arguments from `--player`
- Set the `--player` argument's `type` to `pathlib.Path`
- Set return type of `find_default_player()` to `pathlib.Path`
- Update `--player` and `--player-args` help texts accordingly
- Update `PlayerOutput`:
- Update constructor signature and add typing information
- Rename `cmd` to `path` and remove support for player arguments
- Always build list of arguments and remove Windows-specific logic
- Properly tokenize player input value in `--player-args`
- Log player argv instead of the player command-line string
- Fix now unneeded passthrough URL quotation in `streamlink_cli.main`
- Update docs and fix argparse docs extension
- Update tests and remove Windows-specific player argument tests
- move any sections except for "Command-line usage" (argparse content)
into separate, logical submenus
- rename certain section headers
- fix all references
- slightly rephrase certain things