Add scan screen id and json import

src/bitmessagekivy/main.kv

@@ -214,14 +214,14 @@ MDNavigationLayout:
             id:id_newidentity
         MyAddress:
             id:id_myaddress
-
+        ScanScreen:
+            id:id_scanscreen
     MDNavigationDrawer:
         id: nav_drawer
 
         ContentNavigationDrawer:
             id: content_drawer
 
-    
 <ArrowImg@Image>:
     source: app.image_path +('/down-arrow.png' if self.parent.is_open == True else '/right-arrow.png')
     size: 15, 15

src/bitmessagekivy/screens_data.json

@@ -7,5 +7,9 @@
         "kv_string": "myaddress",
         "name_screen": "myaddress",
         "Import": "from pybitmessage.bitmessagekivy.baseclass.myaddress import MyAddress"
+    },
+    "Scanner": {
+        "kv_string": "scan_screen",
+        "Import": "from pybitmessage.bitmessagekivy.baseclass.scan_screen import ScanScreen"
     }
 }