Reorder sphere coords and align functions

Author: hollasch

books/RayTracingTheNextWeek.html

@@ -1166,9 +1166,9 @@
 with the equations for the corresponding Cartesian coordinates:
 
   $$ \begin{align*}
-      x &= -\cos(\phi) \sin(\theta) \\
       y &= -\cos(\theta)            \\
-      z &= \sin(\phi) \sin(\theta)
+      x &= -\cos(\phi) \sin(\theta) \\
+      z &= \quad\sin(\phi) \sin(\theta)
      \end{align*}
   $$
 </div>