Move all pages to hugo's static/ folder

static/about.html

static/apk.html

static/building.html

static/copyright.html

static/css/styles.css

static/download.html

static/fdroid.html

static/get-involved.html

static/hiring.html

static/hiring/2018-05-java-developer.html

static/hiring/2018-05-usability-consultant.html

static/hiring/2018-05-ux-designer.html

static/how-it-works.html

static/img/apk/confirm-download-cropped.png

static/img/apk/download-complete-cropped.png

static/img/apk/settings-cropped.png

static/img/apk/unknown-sources-cropped.png

static/img/architecture-simple.png

static/img/briar_logo_circle.gif

static/img/briar_logo_large.png