New: Runner : followed Tutorial until <Description>

We'll add a variable to Runner so we can configure its jump velocity.
We'll use a vector instead of just a float so we can profide both a
vertical and horizontal component. Set the corresponding field in the
editor to (1, 7, 0).
We want Runner to jump only when it's touching a platform while the jump
button is pressed. Let's add code for this to the Update method.