Add default translation to config

Add default values because the model wasn't happy that `src_lang` and `tgt_lang` weren't provided

config.json

@@ -29,6 +29,26 @@
   "transformers_version": "4.21.0.dev0",
   "use_cache": true,
   "vocab_size": 256206,
+  "task_specific_params": {
+    "translation_en_to_de": {
+      "early_stopping": true,
+      "max_length": 300,
+      "num_beams": 4,
+      "prefix": "translate English to German: "
+    },
+    "translation_en_to_fr": {
+      "early_stopping": true,
+      "max_length": 300,
+      "num_beams": 4,
+      "prefix": "translate English to French: "
+    },
+    "translation_en_to_ro": {
+      "early_stopping": true,
+      "max_length": 300,
+      "num_beams": 4,
+      "prefix": "translate English to Romanian: "
+    }
+  },
   "tokenizer_class": "NllbTokenizer",
   "max_length": 200
 }