Add a pipeline_tag so that Inference Providers can map their models

Hi,

Setting a proper pipeline_tag would enable us to map an endpoint and serve this model as a third-party Inference Provider.
Thank you

README.md

@@ -1,7 +1,9 @@
 ---
 license: apache-2.0
-extra_gated_description: If you want to learn more about how we process your personal
-  data, please read our <a href="https://mistral.ai/terms/">Privacy Policy</a>.
+extra_gated_description: >-
+  If you want to learn more about how we process your personal data, please read
+  our <a href="https://mistral.ai/terms/">Privacy Policy</a>.
+pipeline_tag: text2text-generation
 ---
 
 # Model Card for Mamba-Codestral-7B-v0.1