feat: addition of local conda installation

[fgypas]

Add option to install zarp-cli with conda from local yaml files

Fixes #36 (issue)

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [X] Documentation update

Checklist

Please carefully read these items and tick them off if the statements are true or do not apply.

• [X] I have performed a self-review of my own code
• [X] My code follows the existing coding style, lints and generates no new warnings
• [ ] I have added type annotations to all function/method signatures, and I have added type annotations for any local variables that are non-trivial, potentially ambiguous or might otherwise benefit from explicit typing.
• [ ] I have commented my code in hard-to-understand areas
• [ ] I have added Google-style docstrings to all new modules, classes, methods/functions or updated previously existing ones
• [ ] I have added tests that prove my fix is effective or that my feature works
• [X] New and existing unit tests pass locally with my changes and I have not reduced the code coverage relative to the previous state
• [X] I have updated any sections of the app's documentation that are affected by the proposed changes

If for some reason you are unable to tick off all boxes, please leave a comment explaining the issue you are facing so that we can work on it together.

[fgypas]

I think that it would be good to add conda tests as well. Should I do that in the same or separate github action?

[fgypas]

No worries. I agree that it's better to build the conda package based on PyPi and not include it here. I will have a look at #37