佔坑，準備開寫。
key:
create project
build(source package *.tar.gz, binary package *.zip)
.rd help of function
description
data and example
Creating R Packages: A Tutorial https://cran.r-project.org/doc/contrib/Leisch-CreatingPackages.pdf
https://community.rstudio.com/t/creating-an-r-package-with-function-sourcing-from-several-scripts/18499/2
