Fix git clone instruction - separate code blocks for Windows and UNIX.

Author: restray

README.md

@@ -41,6 +41,10 @@ Clone kickstart.nvim:
 ```sh
 # on Linux and Mac
 git clone https://github.com/nvim-lua/kickstart.nvim.git "${XDG_CONFIG_HOME:-$HOME/.config}"/nvim
+```
+
+
+```
 # on Windows
 git clone https://github.com/nvim-lua/kickstart.nvim.git %userprofile%\AppData\Local\nvim\ 
 ```