短语挖掘方法

参考博客：

https://www.ruilog.com/notebook/view/7287471fa6e0.html

https://kavita-ganesan.com/how-to-incorporate-phrases-into-word2vec-a-text-mining-approach/#.YQfwAFP7S3I

https://blog.csdn.net/xixiaoyaoww/article/details/105683506