Rewrite/Improve Events guide

[FabianLars]

Also related: #486.

If possible we should look into improving it before the new docs are there. The guide causes too much confusion.

I will try to expand this list every time i see people having issues related to the guide or events.

• It emits events in the setup hook without some kind of condition. (New) users will therefore often encounter timing issues (emitting events before the js side starts to listen to them)
• Usage of unlisten() right after listening to it - idk if it's caused by mindless copy-paste but this was a problem in peoples apps wayyy too often.
• no mention of the need to unlisten in js when something like component unmounting happens.
• no docs on rust to rust communication -> talking about the trigger methods

[simonhyll]

Tracking for 2.0, think we're a bit too close to 2.0 for it to be worth fixing in 1.0. Will definitely need to keep these things in mind when writing a guide on events!

[luis-prates]

Hi, I'm trying to follow the Events guide for both Calling the Frontend from Rust and Calling Rust from the Frontend and I'm having trouble understanding how to listen to the events or create channels using a Rust frontend, in my case, Dioxus, and if I should add tauri as a dependency in the frontend's Cargo.toml as well since the example given on a new Tauri project with Dioxus only has a Tauri command example.

I feel the documentation and even the provided examples such as Learn -> Splashscreen are mostly focused on JavaScript/Typescript frontends, which makes adapting to a Rust frontend difficult.