restructure files and CSS cleanup

[ghost]

This PR partially solves issue #14

recommended: Website Obesity Crisis. Quote: "This is part of a regrettable trend, made possible by faster networks, of having ‘hero images’ whose only purpose is for people to have something to scroll past."

The unusable CSS code was cleaned up and the images were compressed without losing quality.

The theme previously used in Hugo was removed (so many changes were made that they decide not to have the theme).

When deployed statically the website size is just 1.6 Megabytes.

text is too big, a lot of space is unused, a lot of scrolling is required to see little data - direct opposite of decredpower.org

Pages have been restructured.
No longer in on-page mode, if not, normal pagination.

Remaining

"ecosystem of builders" reads weird, "ecosystem" usually refers to the set of products and services, but not people

don't know about you guys but I build for Decred community. Blockchain is an implementation detail. It could be a DAG, or we could play the same consensus game on paper. I work for people like you and me who gather around the great values behind Decred and build stuff to manifest those values.