[Apache] prepare English version of user documentation

[javeme]

Feature Description (功能描述)

At present, the user documentation is in Chinese, and an English version needs to be prepared, and issues also need to guide users to use English.

[javeme]

related issue: #142

[lzm0]

I agree that people should be encouraged to use English when contributing to this project. A long conversation in Chinese does not help developers globally.
Apache also addressed the importance of diversity to the community. https://incubator.apache.org/guides/graduation.html#creating_an_open_and_diverse_community

A good example would be this apache/echarts#16774 (comment)

[javeme]

@lzm0 Thanks for your advice~ Welcome to join and contribute hugegraph

[imbajin]

Done in: https://github.com/apache/hugegraph-doc/tree/master/content/en