Update go-interfaces.tex

Fix typo: "that a look" => "take a look"

go-interfaces.tex

@@ -373,7 +373,7 @@ \subsection{Introspection and reflection}
 
 %% look at layout
 To make the difference between types and values more clear,
-that a look at the following code:
+take a look at the following code:
 \begin{lstlisting}[caption=Reflection and the type and value]
 func show(i interface{}) {
     switch t := i.(type) {