Handle corner cases such as lines with single characters or lines beginning with J

[PigeonF]

The current implementation chokes when a line starts with a capital J, and skips lines that consist of only a single character.

I have added a test with some corner cases I thought of, but was only able to handle them by manually checking for newlines (you can see that extras is set to [] now), as the text would otherwise end up with newlines in them when parsing single characters.

In the repo description it says that this is a mirror of the sourcehut version, but I did not find a mailing list on the sourcehut to send patches to (https://lists.sr.ht/~kareigu/tree-sitter-jjdescription gives 404). If there is some other way to contribute other than through GitHub pull requests, please let me know!

[kareigu]

Thanks for taking a look at this!

This was a compromise I made at the time due to having absolutely no clue what I'm doing in terms of creating a grammar :D

I was originally going to have this mirrored over but since some editors seem to prefer Github for these grammars, I think I'll just move it over here so a PR is just fine :P

I'm currently on a holiday trip so I'll probably take a look at this some time next week once I'm back home.
Thanks again!

[kareigu]

This was great, big thanks!

I've opened a PR on the Helix side to bump the version there.
If you want to follow when it lands upstream: helix-editor/helix#11857