Add `opus-mt-tc` tag

Add `opus-mt-tc` tag so that this new marian models can be found more easily

README.md

@@ -3,10 +3,9 @@ language:
 - en
 - pt
 - pt_br
-
 tags:
 - translation
-
+- opus-mt-tc
 license: cc-by-4.0
 model-index:
 - name: opus-mt-tc-big-en-pt
@@ -20,9 +19,9 @@ model-index:
       type: flores_101
       args: eng por devtest
     metrics:
-       - name: BLEU
-         type: bleu
-         value: 50.4
+    - name: BLEU
+      type: bleu
+      value: 50.4
   - task:
       name: Translation eng-por
       type: translation
@@ -32,9 +31,9 @@ model-index:
       type: tatoeba_mt
       args: eng-por
     metrics:
-       - name: BLEU
-         type: bleu
-         value: 49.6
+    - name: BLEU
+      type: bleu
+      value: 49.6
 ---
 # opus-mt-tc-big-en-pt