Add notice about using SGD in the LSTM tutorial
Add notice about using SGD in the LSTM tutorial

agarbuno/DeepLearningTutorials,ericzhouh/DeepLearningTutorials,pengsun/DeepLearningTutorials,xuezhisd/DeepLearningTutorials,NanYoMy/DeepLearningTutorials,abergeron/DeepLearningTutorials,haojunyu/DeepLearningTutorials,AveRapina/DeepLearningTutorials,shijiaxing/DeepLearningTutorials,FighterLYL/DeepLearningTutorials,sha8e/DeepLearningTutorials,OlafLee/DeepLearningTutorials,webeng/DeepLearningTutorials,ericzhouh/DeepLearningTutorials,agarbuno/DeepLearningTutorials,EugenePig/DeepLearningTutorials,iamtrask/DeepLearningTutorials,mmolero/DeepLearningTutorials,jyb002/DeepLearningTutorials,yukoba/DeepLearningTutorials,cainiaocome/DeepLearningTutorials,cainiaocome/DeepLearningTutorials,pombredanne/DeepLearningTutorials,SYSUNLP/DeepLearningTutorials,mmolero/DeepLearningTutorials,yukoba/DeepLearningTutorials,heaven00/DeepLearningTutorials,jorik041/DeepLearningTutorials,shijiaxing/DeepLearningTutorials,NanYoMy/DeepLearningTutorials,webeng/DeepLearningTutorials,linan7788626/DeepLearningTutorials,EugenePig/DeepLearningTutorials,heaven00/DeepLearningTutorials,iamtrask/DeepLearningTutorials,liangz0707/DeepLearningTutorials,marchick209/DeepLearningTutorials,FighterLYL/DeepLearningTutorials,webeng/DeepLearningTutorials,marchick209/DeepLearningTutorials,sha8e/DeepLearningTutorials,OlafLee/DeepLearningTutorials,xuezhisd/DeepLearningTutorials,jorik041/DeepLearningTutorials,linan7788626/DeepLearningTutorials,liangz0707/DeepLearningTutorials,pombredanne/DeepLearningTutorials,jyb002/DeepLearningTutorials,AveRapina/DeepLearningTutorials,SYSUNLP/DeepLearningTutorials,abergeron/DeepLearningTutorials,pengsun/DeepLearningTutorials,haojunyu/DeepLearningTutorials