fix(betterer 🐛): improve results file escaping

[phenomnomnominal]

Fixes #371

[Svish]

Out of curiosity, why do you do this module require and escaping stuff? Wouldn't it be easier to just use the regular JSON parse and stringify? Or is there a reason why you do what you do instead?

(Not done much Node development, only browser stuff, so just curious🙂)

[phenomnomnominal]

There's a few reasons I went with it, although I'm sure I could convince myself out of it if I did it again!

1. JSON files can't have comments. Since this file is kind of special, it'd be nice to have a header that explained why the file exists and that it shouldn't be modified. If I wanted JSON + the header, I'd have to do custom file handling anyways, so leaning on JS (and require) makes sense.

2. Custom formatting. Having a custom file format means I can be a little bit more particular about how the file is formatted, and therefore write automated updates if I need to change the format. This would be possible with JSON, and of course people could still change the .results file, but people get a bit more nervous about modifying custom file formats (like yarn.lock files or Jest snapshots)

3. The .results file basically is a Jest snapshot - the file format was inspired by Jest, and this PR actually made me think I should probably try to lean more on the Jest internals!

[Svish]

Cool, thanks, makes sense 🙂👍