Fix typos

siunitx.tex

@@ -414,7 +414,7 @@ \subsection{Units}
 \end{LaTeXdemo}
 
 The second operation mode for the \cs{unit} macro is an \enquote{interpreted}
-system, Here, each unit, \acro{SI} multiple prefix and power is given a macro
+system. Here each unit, \acro{SI} multiple prefix and power is given a macro
 name. These are entered in a method very similar to the reading of the unit
 name in English.
 \begin{LaTeXdemo}