Add custom tooltips

[Rayzeq]

Description

This PR add a widget named tooltiped, which is a widget that have eww widgets inside its tooltip instead of only text.

Usage

For example you can put an image inside a tooltip like this:

(tooltiped
    (image :path "/home/....")
    (label :text "example")
)

Showcase

This allow doing thing like this for example:

Checklist

• All widgets I've added are correctly documented.
• I added my changes to CHANGELOG.md, if appropriate.
• The documentation in the docs/content/main directory has been adjusted to reflect my changes.
  This folder doesn't exist, I assume you mean docs/src, which I don't think I need to update.
• I used cargo fmt to automatically format all code before committing

[elkowar]

Thanks! This is really cool!