Update README.md

Author: bantic

README.md

@@ -6,6 +6,7 @@ brew install vim
 brew install the_silver_searcher
 brew install bash-completion # optional
 brew install git # suggested, required for bash completion
+brew install tmux
 git clone git@github.com:201-created/pear.git ~/.pear
 # if using bash:
 echo "source ~/.pear/bash.sh" >> ~/.bash_profile