[DOCS] x-on .dot modifier missing in documentation

[benjaminfayaz]

The .dot modifier when using x-on (or @) is useful when combined with e.g. bootstrap events, which might contain dots.
Since @show.bs.collapse="menuIsOpen = true" does not work, one can use @show-bs-collapse.dot="menuIsOpen = true".

This should be included in the documentation. Currently it can only be found by looking at the source code.

[SimoTod]

https://github.com/alpinejs/alpine/blob/main/packages/docs/src/en/directives/on.md the relevant section is here if you want to send a PR

[benjaminfayaz]

#2253 🚀