[pkg] add a convenience target for installing deps

Makefile

@@ -12,6 +12,9 @@ clean:
 icon:
 	make -C icon
 
+get_deps:
+	 sudo apt install libzmq3-dev libgtk-3-dev libappindicator3-dev golang pkg-config
+
 
 LANGS ?= $(foreach path,$(wildcard locales/*/messages.gotext.json),$(patsubst locales/%/messages.gotext.json,%,$(path)))
 empty :=