reorganize modules

modules/client_about/about.lua

@@ -0,0 +1,18 @@
+About = {}
+
+-- private variables
+local aboutWindow
+
+-- public functions
+function About.create()
+  aboutWindow = UI.display('about.otui', { locked = true })
+end
+
+function About.destroy()
+  aboutWindow:destroy()
+  aboutWindow = nil
+end
+
+function About.openWebpage()
+  displayErrorBox("Error", "Not implemented yet")
+end