Added Russian to the list of languages.

docs/languages.json

@@ -9,6 +9,11 @@
         {
             "name": "한국어 (Korean)",
             "translation": "Translation by Kiman Kim"
+        },
+        "ru":
+        {
+            "name": "Ру́сский (Russian)",
+            "translation": ""
         }
     }
 }

docs/ru/tutorials/war-battles.md

@@ -1 +0,0 @@
-