fix: re-add plugin init to cli docs (tauri-apps#503)

Author: FabianLars

docs/.templates/cli.md

@@ -24,6 +24,12 @@ This command is pretty helpful when you need to have a quick overview of your ap
 
 {init}
 
+## `plugin init`
+
+<Command name="plugin init" />
+
+{plugin init}
+
 ## `dev`
 
 <Command name="dev" />