Port experiment layout to hexo

* Use accordion as an example
* Create experiment header and footer partials
* Update the page title based on experiment
* Switch to experiment template if page is an experiment
Use experiment wrapper class to modify base styles
Add clock experiment
Add 2d cube experiment
Add 3d cube experiments
Add media query listener experiment
Add modal experiment
Add parallax experiment
Add early perspective experiment
Add pyramid experiment
Add sphere experiment
Add webcam experiments
Move experiment js to after the jQuery include
Don't style generic <section>s in experiments
Add a friendlier experiment title

* Create experiment body and header styles
* Remove old Facebook and Twitter button styles, buttons have been
removed
* Remove experiment’s h1 styles
Fix parallax experiment in new layout

* Don’t use position: fixed, absolute is fine
* Tweak experiment region boundaries so that parallax can go right to
the edges
Tweak clock experiment for new layout
Fix 2d cube experiments in new layout
Tweak 3d cube experiment

* Prevent scrolling with up and down keys
* Tweak vertical spacing
Tweak sphere controls

* Position closer to top