Set `<start_of_turn` and `<end_of_turn>` to be special tokens (#2)

tokenizer.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:2f1f411054535bfe0e360e3431e7340cfc795d0d4ed1ebd426b01993831d49e4
-size 17525359
+oid sha256:9cf8cddb82b68ab495546855952d707acfa17f23c97031e0cf346b207d73faae
+size 17525357

tokenizer_config.json

@@ -856,7 +856,7 @@
       "normalized": false,
       "rstrip": false,
       "single_word": false,
-      "special": false
+      "special": true
     },
     "107": {
       "content": "<end_of_turn>",
@@ -864,7 +864,7 @@
       "normalized": false,
       "rstrip": false,
       "single_word": false,
-      "special": false
+      "special": true
     },
     "108": {
       "content": "\n",