Moved menus into their own folder, stubbed bunch of menus

lib/states/menus/credits_menu.rb

@@ -0,0 +1,18 @@
+class IMICRTS
+  class CreditsMenu < CyberarmEngine::GuiState
+    def setup
+      background [0xff7b6ead, 0xff7a0d71, 0xff7a0d71, 0xff7b6ead]
+
+      stack(height: 1.0) do
+        background [0xff555555, Gosu::Color::GRAY]
+
+        label "About I-MIC-RTS", text_size: 78, margin: 20
+        label "Words go here.\nMore words also go here. Thank you and have a nice day."
+
+        button("Back", width: 1.0, margin_top: 20) do
+          push_state(MainMenu)
+        end
+      end
+    end
+  end
+end