[feat] add tmux conf link

mklink.sh

@@ -14,6 +14,13 @@ fi
 
 ln -sf "`pwd`/.gitconfig" "$HOME/.gitconfig"
 
+if [ -f "$HOME/.tmux.conf" ]; then
+  # backup old file
+  mv "$HOME/.tmux.conf" "$HOME/.tmux.conf.old"
+fi
+
+ln -sf "`pwd`/.tmux.conf" "$HOME/.tmux.conf"
+
 if [ ! -d "$HOME/.ssh" ]; then 
   mkdir -p "$HOME/.ssh"
 fi