fix "from env" newline handling

[xav-ie]

Many (at least the ones I have encountered) env loaders replace "\n" with a
literal newline character when loading an env variable. I need this change in
my personal config and I think others would also prefer this default.

[fdncred]

I wonder how this will work on Windows since Windows uses \r\n.

[xav-ie]

hmm. that is good question.

Here is what I find from other env loader:
https://github.com/dotenvx/dotenvx/blob/79b04e3e46d62362e2ad2415bd8aca91f59db87f/src/lib/helpers/parse.js#L123-L127
^ It looks like we should also replace carriage return and tabs, too!
This is a good catch. I will update pr now

[xav-ie]

I updated the PR. I am happy to amend the right hand of the replacement to use (char newline), (char carriage_return), and (char tab). Please just let me know! I appreciate the feedback.

[fdncred]

I'm not sure how this'll work but let's try it.