feat: create scripts to make champagne cli work OOTB

[kelly-sovacool]

Changes

Create bin/champagne (bash script) and main.py so that the champagne CLI will work out-of-the-box without the need to run pip install, so long as required Python packages that are not part of the standard library are installed (currently: click & cffconvert).

The Python dependencies are available in the shared py311 conda env, which can be activated before using the script:

. "/data/CCBR_Pipeliner/db/PipeDB/Conda/etc/profile.d/conda.sh"
conda activate py311
bin/champagne --help

How it works

bin/champagne calls main.py, which adds src/ to the python path and then calls the main function in src/__main__.py. Manually adding this src dir to the path is the key ingredient that allows users to call bin/champagne from anywhere and it will be able to import the python modules defined in src.

Issues

resolves #179

PR Checklist

(Strikethrough any points that are not applicable.)

• This comment contains a description of changes with justifications, with any relevant issues linked.
• [ ] Write unit tests for any new features, bug fixes, or other code changes. testing framework not yet implemented
• [ ] Update docs if there are any API changes. on hold until before public release
• [ ] If a new nextflow process is implemented, define the process container and stub.
• Update CHANGELOG.md with a short description of any user-facing changes and reference the PR number. Guidelines: https://keepachangelog.com/en/1.1.0/