Interpolate text into html! macro, remove text! macro

[chinedufn]

What

This PR makes it much easier to interpolate text variables into your HTML.

Before (bad)

let my_text = "hello world";

html! { <div> { text!(my_text) } </div> }

After (good)

let my_text = "hello world";

html! { <div> { my_text } </div> }

Why

Needing a macro for such a common thing was a poor experience

[chinedufn]

Published!

virtual-dom-rs = "0.6.5"

[dbrgn]

Cool!