feat(mini.jump): Add idle timeout to stop jumping automatically

[annenpolka]

• I have read CONTRIBUTING.md
• I have read CODE_OF_CONDUCT.md

This PR adds timeout after idle feature, inspired by lightspeed.nvim.
With this feature, you can reset highlights automatically, and start searching for another character easily.

The default value is set to 10^7, so it won't break behavior compatibility.

[echasnovski]

This is great! Both idea and execution.

Couple of remarks:

• Please, generate documentation automatically from annotation comments. Inside Neovim run :luafile scripts/minidoc.lua.
• For a better consistency across modules, I think it is better to not introduce "timeout" notion along with "delay". The best solution here seems to make a breaking change: soft deprecate highlight_delay and introduce delay = { highlight = 250, idle_stop = 10000000 }. This means (at least) updating MiniJump.config (both with documentation), H.setup_config() (update validation logic and notification message if user actually supplied highlight_delay), and all usages of highlight_delay. If this feels a bit overwhelming, I am happy to do it myself (either by pushing to this PR or merging this to a different branch and continue there). If not, I am also happy to guide through this process.

[annenpolka]

Firstly, thank you for your kind and in-depth review, and I'm so sorry I overlooked the info about document generation. I'm sure I have made you feel uncomfortable.

I made the changes you reviewed.
I'm a noob developer and bad at English, so there may be some mistakes in both implementation and document wording.

[echasnovski]

No "uncomfortable" on may end: it is a great PR with useful feature, attention to both details (apart from automatic documentation generation :) ) and code style.

There is some refactoring I would like to do here, but I won't bother you with this.

Thanks for PR!