安装vim及配置参考

参考：https://blog.csdn.net/qq_42138566/article/details/82800451

http://www.runoob.com/linux/linux-vim.html

安装时出现问题：

Package vim is not available, but is referred to by another Package.
This may mean that the package is missing, has been obseleted, or 
is only available from another source

参考：https://askubuntu.com/questions/101809/package-vim-has-no-installation-candidate