如何画流程图

ob上的流程图是基于Mermaid
参考
https://www.runoob.com/markdown/md-advance.html?tdsourcetag=s_pctim_aiomsg
https://mermaid-js.github.io/mermaid/#/examples
https://mermaid-js.github.io/mermaid-live-editor/
https://www.cnblogs.com/wuyida/p/6301240.html
by翰墨水木