Add code frame

[SimenB]

I find it easier to locate the error with a than just the index of the error. E.g. trailing comma in an object:

Note: This drops support for node 4

I left out tests in case you don't want this

[SimenB]

Fixed the linting error I introduced, what should I do about the other ones?

[sindresorhus]

I totally missed this one... Can you fix the merge conflict?

You also need to update the readme.

Maybe also an example.js that shows how the output looks like with the code frame.

[SimenB]

Maybe also an example.js that shows how the output looks like with the code frame.

The updated readme shows this (albeit without colors), do you want anything more?

[sindresorhus]

Looks good :)