Revert "changed some absolute paths to relative so it will work in gh-pages"

This reverts commit 30fe6db05e10c23eb21dec3811f18a35a0a7b773.
Merge branch 'gh-pages' of github.com:Siyavula/ThunderboltKids into gh-pages

Conflicts:
	science-adventures.html
Merge branch 'gh-pages' of github.com:Siyavula/ThunderboltKids into gh-pages