Include line numbers in output

I'd like to add a new `lineNumberRange` field to the output which will be useful in another project I'm working on (https://github.com/joshwnj/inline-docs).
> Line 2 was being skipped (sequence was `[0, 2, 3, ...]`).

I don't understand. Do you have a test case?

What I can see is the `\n` is actually considered to belong to the next line, but I don't see a case where this results in a skipped line.

> In the case of the final line not ending in a \n char, the final line would not be added to the index.

I can't reproduce either. Just note that the lines are numbered from 0 (unlike most text editors, it's more like getting the index of an array of lines).