Sort-lines

Changed

- Return 0 when lines have been sorted successfully.

A non-zero return code is reserved for when the tool has not been able to do its job.

Added

- The pragma can be passed options: `pragma: alphabetize[options]`.

Option | Effect
------------------------ | --------------------------------------------
`cs`, `case-sensitive` | all upper-case letters before all lower-case
`ci`, `case-insensitive` | sorted without regard for case

The default behaviour remains case-sensitive.

- The default case-sensitivity can be controlled on the command line.

Use `--case-insensitive` to make all sorting case-insensitive
unless specified to be case-sensitive explicitly.
`--case-sensitive` can also be used;
this is the default.

Fixed

- An empty line (whitespace only) did not end the sorting block.
Now it does.

Fixed

- `pre-commit` example configuration in README used an incorrect project/hook name
- The package was not built correctly, causing an error:

pytb
ModuleNotFoundError: No module named 'sort_lines'

First release.