Update cheat_sheet.md

cheat_sheet.md

@@ -1,12 +1,34 @@
 # VIM Cheat Sheet
 
-## Install vim-plug
+## Setup
+
+### Install vim-plug
 
 ```
 curl -fLo ~/.vim/autoload/plug.vim --create-dirs \
     https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim
 ```
 
+clone repo and
+
+```
+ln -s /path/to/cloned/repo/.vimrc ~/.vimrc
+```
+
+then open vim and
+
+```
+:PlugInstall
+```
+
+then
+
+```
+source ~/.vimrc
+```
+
+or reopen vim
+
 ## Split
 
 - `<ctrl-w>s` or `:sp` split with line running horizontally