Create a command line executable

[AdrianDAlessandro]

Description

This PR does a few things towards achieving #32, it:

• Renames the package from src to autocorpus (package naming convention recommends all lowercase and no underscores)
• Moves the run_app.py script into the autocorpus package and makes it runnable as a main package script (ie python -m autocorpus)
• It makes a command-line executable script auto-corpus than can be run directly without python -m
• It updates the "Getting Started" section of the readme to reflect the above and installation with Poetry

Fixes #72

Type of change

• Documentation (non-breaking change that adds or improves the documentation)
• New feature (non-breaking change which adds functionality)
• Optimization (non-breaking, back-end change that speeds up the code)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (whatever its nature)

Key checklist

• All tests pass (eg. pytest)
• The documentation builds and looks OK (eg. mkdocs)
• Pre-commit hooks run successfully (eg. pre-commit run --all-files)

Further checks

• Code is commented, particularly in hard-to-understand areas
• Tests added or an issue has been opened to tackle that in the future. (Indicate issue here: # (issue))

[Thomas-Rowlands]

Ran fine & thanks for this rename, its been a personal pet peeve of mine for some years now!