Fixing typo in Tutorial (#718)

docs/00 Quick Start/Tutorial.md

@@ -29,7 +29,7 @@ Let's consider their props.
 
 * It is tempting to give `Square` its position via props, but this, again, is not necessary, because the only information it really needs for the rendering is the color. I'm going to make `Square` white by default, and add a `black` boolean prop. And of course `Square` may accept a single child: the chess piece that is currently on it. I chose white as the default background color to match the browser defaults.
 
-* The `Board` is tricky. It makes no sense to pass `Square`s as children to it, because what else could a board contain? Therefore it probably owns the `Square`s. But then, it also need to own the `Knight` because this guy needs to be placed inside one of those `Square`s. This means that the `Board` needs to know the knight's current position. In a real Chess game, the `Board` would accept a data structure describing all the pieces, their colors and positions, but for us, a `knightPosition` prop will suffice. We will use two-item arrays as coordinates, with `[0, 0]` referring to the A8 square. Why A8 instead of A1? To match the browser coordinate orientation. I tried it another way and it just messed with my head too much.
+* The `Board` is tricky. It makes no sense to pass `Square`s as children to it, because what else could a board contain? Therefore it probably owns the `Square`s. But then, it also needs to own the `Knight` because this guy needs to be placed inside one of those `Square`s. This means that the `Board` needs to know the knight's current position. In a real Chess game, the `Board` would accept a data structure describing all the pieces, their colors and positions, but for us, a `knightPosition` prop will suffice. We will use two-item arrays as coordinates, with `[0, 0]` referring to the A8 square. Why A8 instead of A1? To match the browser coordinate orientation. I tried it another way and it just messed with my head too much.
 
 Where will the current state live? I really don't want to put it into the `Board` component. It's a good idea to have as little state in your components as possible, and because the `Board` will already have some layout logic, I don't want to also burden it with managing the state.