Change from SCSS to plain CSS

[mawiswiss]

To use the reset for example in react projects with styled-components we need to have the file available in plain CSS. We discussed this issue already earlier in #4.

As it's a breaking change we need to bump the version to 2.0.0.

[mawiswiss]

We're ready here.

@j3ll3yfi5h Do you have any breaking styling changes? It's would be the time to introduce it now. I noticed some issues with the button styling (border) and the white background on html/body.

[j3ll3yfi5h]

@marcwieland95

Please add:

html {
	height: 100%;
}

body {
	min-height: 100%;
}