Implement vertical menu functionality

1. Add jQuery library
2. Toggle vertical menu items on click
3. Make all the menu items visble if JS
is switched off
Make up main content block layout
Make up footer layout
Add gallery to the top
Try to add sticky elements

Almost got it, but have some problems
with right panel - it move to the left side
of container becoming sticky.
Sticky creation method calling commented. Will fix
in next commits