Add LSTM figure

Section06-Neural-Machine-Translation/section06.tex

@@ -1153,6 +1153,16 @@ NLP问题的隐含结构假设 & 无隐含结构假设，端到端学习 \\
 \item LSTM
 \end{itemize}
 %%% 图
+\begin{center}
+    \begin{tikzpicture}
+        \tikzstyle{wordnode} = [font=\normalsize,align=left]
+        \tikzstyle{auxnode} = [inner sep=0pt,outer sep=0pt,opacity=50,draw=red,fill=red,circle,minimum size=3pt]
+
+        \begin{scope}
+            \node[auxnode,label={[label distance=1pt,font=\tiny,inner sep=0pt]-45:00}] (aux00) at (0,0) {};
+        \end{scope}
+    \end{tikzpicture}
+\end{center}
 \end{frame}
 
 %%%------------------------------------------------------------------------------------------------------------