Add edge descriptions to pot file (translation catalog)

scripts/boxes2pot

@@ -45,6 +45,7 @@ class Boxes2pot:
         self.boxes = {b.__name__ : b() for b in boxes.generators.getAllBoxGenerators().values() if b.webinterface}
         self.groups = boxes.generators.ui_groups
         self.groups_by_name = boxes.generators.ui_groups_by_name
+        self._readEdgeDescriptions()
 
     def add(self, msg, comment=None, reference=None):
         if not msg or msg in self.message_set:
@@ -56,6 +57,12 @@ class Boxes2pot:
         modulenames = modulename.split(".")
         return "/".join(modulenames) + ".py"
 
+    def _readEdgeDescriptions(self):
+        for char, descr in edges.getDescriptions().items():
+            self.add(descr, f"{char} edge description", "boxes/edges.py")
+            self.add(f"{char} {descr}", f"{char} edge description",
+                     "boxes/edges.py")
+
     def addBoxParams(self, name, box, location=None):
         for group in box.argparser._action_groups:
             if not group._group_actions:
@@ -79,7 +86,7 @@ class Boxes2pot:
                     if isinstance(c, (float, int)):
                         continue
                     self.add(c, "possible choice for " + name, location)
-    
+
     def readBoxes(self):
         for group in self.groups:
             location = "boxes/generators/__init__.py"