Add implementation of Coulomb's Law

[ovynnej]

Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}. (Not applicable to this PR.)

[ovynnej]

I modeled this implementation of Coulomb's Law on this project's preexisting implementation of Ohm's Law written by @erdum with workshopping by @cclauss.

Thanks in advance for the review! And sorry, I submitted another identical PR a few minutes ago but I decided to close it because there were some problems when I tried to make a followup commit and PR. I hope that simply closing that PR and creating this PR is less of a bother for folks than it would have been to help me troubleshoot that -- I know maintainers have a lot on their plates for Hacktober!

[poyea]

Thank you for your pull request!🤩