Extend spec

[rktjmp]

RFC on docs if possible, @savq @kunzaatko

[rktjmp]

Better link I think: https://github.com/rktjmp/lush.nvim/pull/23/files#diff-0aeed55bea344e264dccb1c6b15c1a0adbd2461f98e072b7663a6ad486254999R325

diff seems more readable than I thought it would be.

[savq]

• I like the explicit mention of potential use cases.

• Also good to mention the precedence rules.

• Remember to add the new section in the TOC.

• The other stuff is more formatting specific, I'll make a commit for that.

[rktjmp]

Ya, added to TOC already. Make sure youre looking at the latest version, I had an old link in the initial post.

[savq]

Made #25. Most changes are fixing typos and adding capitals. I only changed a couple sentences.