[zsh] Simplify shared config

clone_and_link.sh

@@ -9,7 +9,8 @@
 
 if [[ $1 == "shared" ]]; then
     ln -Tsfv $PWD/zsh $HOME/.zsh
-    ln -Tsfv ~/.zsh/.zshrc_shared $HOME/.zshrc
+    ln -Tsfv ~/.zsh/.zshrc $HOME/.zshrc
+    touch ~/.zsh/.shared_config
     ln -Tsfv $PWD/tmux $HOME/.tmux
     ln -Tsfv ~/.tmux/.tmux.conf $HOME/.tmux.conf
     mkdir -p $HOME/.config