Add cuisine=ethiopian support (more than 500 uses)

threshold based on openstreetmap#1573

Author: matkoniecz

data/fields/cuisine.json

@@ -79,6 +79,7 @@
             "argentinian": "Argentinian",
             "balkan": "Balkan",
             "bavarian": "Bavarian",
+            "ethiopian": "Ethiopian",
             "shawarma": "Shawarma",
             "persian": "Persian",
             "middle_eastern": "Middle Eastern",