My tweaks

[joeytwiddle]

Hi Dmitry, I'm not expecting you to merge this request, but I thought you might like to see how I'm using AsyncFinder a bit differently. (I've skipped folder matches, to focus on filenames. But perhaps in future I would like it to put filename matches at the top, and keep folder matches below. VSCode and WebStorm do something like that.)

You might like to take the changes I made to the syntax file. Line highlighting wasn't working for me, so I relaxed AsyncGrepLine to avoid overlapping with AsyncGrepFile. Then I added a container to stop the relaxed AsyncGrepLine from leaking into the actual result text.

Additional: I also made some comments on your "latest" commit. 😉