Working on specifying a .env path with a string

[groovenectar]

As someone not well-versed in Rust yet, only a fan, this update in this project turns out to be non-trivial

But I did update some README files, so I'd like to draft a pull request as I've been pondering this feature for quite some time

I plan to revisit this, but would definitely appreciate any help or pointers

This addresses some posted issues such as #945

[casey]

Thanks for the PR! just is definitely non-trivial to work on, there are a lot of layers (lexer, parser, error handling, documentation, etc) to modify.

I think it would probably be better to add a new setting, dotenv-path, which takes a string.

As far as pointers, check out the tempdir setting, since takes a string, and dotenv-path will probably have a similar implementation.

[casey]

This wound up being implemented in #1692.