expand quickspell rules in overview

CS/overview.tex

@@ -124,6 +124,9 @@ If your Initiative is below 0, you get a cumulative -1 penalty.
 
 	\item{Standard spells require 1 round to cast per level.}
 	\item{Quick spells only need 3 Initiative + the spell's level, so a 2nd level spell requires 5 Initiative.}
+	\begin{itemize}
+		\item{You cannot cast a quick spell using the highest-level spells in that sphere.  If you have Fate 3, you can only cast level 1 and 2 Fate spells as Quick Spells.}
+	\end{itemize}
 	\item{Ritual spells require a full, uninterrupted scene to cast, and count as \textit{Resting Actions}.}
 
 \end{itemize}