Implemented overwrite guardrails thanks to @tjlaboss.

[MicahGale]

Description

This introduces a new argument to MCNP_Problem.write_to_file, (and montepy.input_parser.input_file.write_to_file.open), overwrite, which indicates if the existing file should be overwritten. The default behavior is to raise a FileExistsError if the file exists, and overwrite is not specified. This error is ignored in overwrite=True. No matter what a IsADirectoryError is raised if the path is a folder.

Thanks @tjlaboss for the prototyping.

Fixes #442

Checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation (if applicable)
• I have added tests that prove my fix is effective or that my feature works (if applicable)

[MicahGale]

Do you think this change counts as a minor or patch version change?

[MicahGale]

I need to update the getting started guide accordingly.

Completed.

[tjlaboss]

Do you think this change counts as a minor or patch version change?

MINOR version when you add functionality in a backward compatible manner
PATCH version when you make backward compatible bug fixes

This fits the description of MINOR version more closely than PATCH version I'd say.

[tjlaboss]

Nice to see that #439 is useful.

[MicahGale]

Do you think this change counts as a minor or patch version change?

MINOR version when you add functionality in a backward compatible manner
PATCH version when you make backward compatible bug fixes

This fits the description of MINOR version more closely than PATCH version I'd say.

Ok I'll update docs to say version 0.3.0. Yay we are off the rails of running into the version 0.2.15 train on test-pypi