Set `library_name` to `tf-keras`.

Model 'keras-io/TF_Decision_Trees' seems to be compatible only with "Keras 2" and not "Keras 3". To distinguish them, models compatible with legacy Keras 2.x should be tagged as `tf-keras` while models compatible with Keras 3.x are tagged as `keras`.

This PR updates the model card to replace the explicit `library_name: keras` metadata which is now outdated by `library_name: tf-keras`. Updating this metadata will facilitate its discoverability and usage.

For more information about `keras` and `tf-keras` library names, check out this pull request: https://github.com/huggingface/huggingface.js/pull/774.

README.md

@@ -1,33 +1,24 @@
 ---
-thumbnail:
-
-tags:
-- tabular-classification
-- keras
-- tensorflow
-
-library_name: keras
-
-
+library_name: tf-keras
 license: apache-2.0
-
 metrics:
 - accuracy
-
+tags:
+- tabular-classification
+- tensorflow
 model-index:
 - name: TF_Decision_Trees
   results:
-  - task: 
+  - task:
       type: structured-data-classification
     dataset:
-      type: census
       name: Census-Income Data Set
+      type: census
     metrics:
     - type: accuracy
       value: 96.57
     - type: validation loss
-      value: 0.227394    
- 
+      value: 0.227394
 ---
 
 # TensorFlow's Gradient Boosted Trees Model for structured data classification