Use Jekyll includes for HTML.

	new file:   _includes/header_nav.html
	modified:   _layouts/default.html
	modified:   index.html
Add header icon images.

	new file:   assets/icon/top-tray-b.png
	new file:   assets/icon/top-tray-bx2.png
	new file:   assets/icon/top-tray.png
	new file:   assets/icon/top-trayx2.png
Header navbar layout.

	modified:   _includes/header_nav.html
	modified:   _layouts/default.html
	new file:   assets/kalamari.css
	modified:   assets/style.css