Add error explanation for js tech errors

[doochik]

Example

Error: Unexpected token: name (foo) (line: 7437, col: 12, pos: 312592)
  7435 |        };
  7436 |    } else {
  7437 |        let foo = 'bar';
--------------------^
  7438 |        result = {
  7439 |            result: 0

[qfox]

Oh, you! Code stealer!

[doochik]

Let's create framework for this! =)

[qfox]

Yeah, that's what I'm trying to do at https://github.com/violence/warnie ;-D

[doochik]

afaik, csso uses the same error explain code