Removed' example from 'example-footer'
Changed all sass files to partial files

So that only one file is created as a css file, I've added the partial
underscore in fron of every file, as sass reconises this, and doesn't
compile these files into css. So the filing structure is much, much
cleaner.
Fixed the menu sidebar to fix in a specific y position
Updated the entity on this page to match the actual code.
Minor tweaks due to the renaming of sass files