Add Command R+ to HuggingChat config (#1001)

* Add Command R+ model

* add token limits & default sampling parameters

* Make Command R+ the default

Author: nsarrazin

.env.template

@@ -1,7 +1,21 @@
 # template used in production for HuggingChat.
 
 MODELS=`[
-    {
+  {
+    "name" : "CohereForAI/c4ai-command-r-plus",
+    "tokenizer": "Xenova/c4ai-command-r-v01-tokenizer",
+    "description": "Command R+ is Cohere's latest LLM and is the first open weight model to beat GPT4 in the Chatbot Arena!",
+    "modelUrl": "https://huggingface.co/CohereForAI/c4ai-command-r-plus",
+    "websiteUrl": "https://docs.cohere.com/docs/command-r-plus",
+    "logoUrl": "https://huggingface.co/datasets/huggingchat/models-logo/resolve/main/cohere-logo.png",
+    "parameters": {
+      "stop": ["<|END_OF_TURN_TOKEN|>"],
+      "truncate" : 24576,
+      "max_new_tokens" : 8192,
+      "temperature" : 0.3
+    }
+  },
+  {
     "name" : "mistralai/Mixtral-8x7B-Instruct-v0.1",
     "description" : "The latest MoE model from Mistral AI! 8x7B and outperforms Llama 2 70B in most benchmarks.",
     "logoUrl": "https://huggingface.co/datasets/huggingchat/models-logo/resolve/main/mistral-logo.png",
@@ -153,7 +167,7 @@ MODELS=`[
           "prompt": "How do I make a delicious lemon cheesecake?"
         }
       ]
-    },
+    }
 ]`
 
 OLD_MODELS=`[