Update makefile to handle updates

Makefile

@@ -1,10 +1,15 @@
-.PHONY: clean install
-
+.PHONY: default
 default: install
 
+.PHONY: install
 install:
 	sh ./vim-sync-append.sh
 
+.PHONY: update
+update:
+	sh ./update-plugins.sh
+
+.PHONY: uninstall
 uninstall:
 	rm ~/.vimrc
 	rm ~/.nvimrc
@@ -12,6 +17,7 @@ uninstall:
 	rm -fr ~/.nvim
 	rm -fr ~/.config/nvim
 
+.PHONY: clean
 clean:
 	rm -fr ./vim/plugged
 	rm -fr ./vim/autoload/plug.vim