Darren Schroeder

I tried to update this old PR to the latest main. May have missed some things. One thing that doesn't work is: ```nushell let a = r"one\ntwo\n (blah) ($var)" ```...

Ugh, this is going to take some surgery. parse_value is not passing the right span to parse_raw_string. If anyone wants to pick this up and take it over, please volunteer....

I had to change the syntax to `r#" blah "#` for easier parsing. Had to add code to lex.rs because it was lexing raw strings incorrectly. This works now. ```...

> I like the robustness of the rust like syntax you picked. Makes sense on the parsing side to me. Unsure if we really need the separate `Value::RawString` especially now...

@WindSoilder I looked through the latest changes and it's looking good!!! I'm still voting to keep `Value::RawString`, `Expr:RawString`, `Type::RawString`, and `SyntaxShape::RawString` for now. What I'd like to see is we...

> Meaning that these string types aren't fully raw strings. So, this PR adds raw strings (r##) with variable number of # to be able to enclose any string. Slight...

@IanManske what about this compromise? - Begin `r@` - End `@` - Increase `@` to escape at signs in the string - Only works on single quotes I think that...

I kind of always considered the `r` as meaning, "this is going to be a raw-string". So, my preference would be to keep it. Plus, I think `@'string'@` is weirder...

It would be great to color aliases and custom commands as something different than internal calls.

I'm guessing that this would require a collect vs streaming data because we'd have to know whether it was one entry or multiple. It may be possible to cache the...