feat: add feature flags

Flags allow you to disable certain functionality and compile with only select features to reduce build time.

Resolves #54.

src/modules/launcher/mod.rs

@@ -294,8 +294,6 @@ impl Module<gtk::Box> for LauncherModule {
                     }
                 }
             }
-
-            Ok::<(), swayipc_async::Error>(())
         });
 
         Ok(())