feat: add support for .ini files

[adam-moss]

Adds support for .ini files.

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[tfroseman]

Thanks for the pull request! INI format is flexible though public usage appears to favor the usage of a ; (semicolon) over the # (hash). Given the chance different parsers may not use one over the other, I want to spend a bit more time looking at different implementations before merging this. Though I am leaning toward accepting this as is. Most likely this is a historical convention and both notations are fully supported in the majority of cases.