Add typehints, missing documentation & formatting

[lfse-slafleur]

The following changes are proposed:

• Fix formatting of the file by changing all tabs to just 4 spaces. Previously, tabs and spaces were both used.
• Add typehints where possible. Either fix or suppress issues.
• Add documentation.

[sloisel]

I have yet to put in github automation for my unit tests, can you just tell me if you unit tested this?

[codecov]

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[lfse-slafleur]

I have yet to put in github automation for my unit tests, can you just tell me if you unit tested this?

Apologies for a later reply! Yes, I had run each of the tests.

Thanks for merging! Hope it helps :D