MakeToLearn+website

1) replace tag box in upload page with list of categories

Categories: (need to fill this out)
 * classroom example
 * tutorial
 * elementary school
 * middle school
 * high school
 * post-secondary
 * physical science
 * physics
 * prototypes
 * mathematics
 * engineering
 * mechatronics
 * 3D printing
 * Add an add a category button

filter at the top of the individual categories page:
 * alphabetical
 * date uploaded
 * most viewed

2) search box for just videos

3) separate about us videos page