Improve accessibility

[VictorCazanave]

• Resolve Support keyboard navigation #82
• Fix color property validator

As mentioned in the issue, the <input/> is still accessible/focusable and natively reacts to keyboard events.
However I think each screen reader has different rules (like browsers) and this post says ChromeVox screen reader doesn't read content with 0 opacity.
Another solution could be to set opacity to 0.001. Anyway the <input/> has a position: absolute, so it's hidden by the toggle button (if the color isn't transparent of course).

I didn't notice any regression on the demo page but if you have time, you can double check 😄

[euvl]

Role & aria-checked were there, so that screen readers knew that all HTML elements are one component (element) and would consider it to be one checkbox. As far as I know, it will not try to interpret what is inside an element if role & state is there

[VictorCazanave]

All the examples I've found (MDN, W3C...) use role and aria-checked on a <span>/<div> without any <input> (the checkbox behaviour is done in JS) and the W3C validator says using these attributes on a <label> is an error.
So I thought that since the <input> is now accessible, we don't need to handle the aria attributes anymore.
But I don't know so much about accessibility and what you said makes sense 🤔
Do you want me to put role and aria-checked back?

[Artem-Schander]

I have no idea why there are not many more people wanting this.
In my opinion it is an must have, so it would be nice if this request could be merged