Add metadata link to newer version of the model

We've just shipped a new metadata field that allows you to link to a newer model version. See https://huggingface.co/CohereForAI/c4ai-command-r-plus as an example. This PR links this model to https://huggingface.co/nomic-ai/nomic-embed-text-v1.5. Let me know if you have any questions

README.md

@@ -2,11 +2,11 @@
 library_name: sentence-transformers
 pipeline_tag: sentence-similarity
 tags:
-  - feature-extraction
-  - sentence-similarity
-  - mteb
-  - transformers
-  - transformers.js
+- feature-extraction
+- sentence-similarity
+- mteb
+- transformers
+- transformers.js
 model-index:
 - name: epoch_0_model
   results:
@@ -2605,6 +2605,7 @@ model-index:
 license: apache-2.0
 language:
 - en
+new_version: nomic-ai/nomic-embed-text-v1.5
 ---