00-readU.Rmd

# 杂七杂八{# extra}

This is a document describe the build procedure.
The other branch "gh-pg"(or something like this) 是用于用alternative approach去在github publish 这本书，但是做到一半没做下去，卡在[这里](https://bookdown.org/yihui/bookdown/github.html)，中，Create a token之后，没做到encrypt it.然后改用docs发布发现一次成功就不想试了。