documentation: Include FeatureGroup's load_feature_definitions API documentation (#4165)

* documentation: Include FeatureGroup's load_feature_definitions
documentation

* Escape underscore in type names

Author: martinRenou

doc/api/prep_data/feature_store.rst

@@ -6,7 +6,6 @@ Feature Group
 
 .. autoclass:: sagemaker.feature_store.feature_group.FeatureGroup
     :members:
-    :exclude-members: load_feature_definitions
     :show-inheritance:
 
 .. autoclass:: sagemaker.feature_store.feature_group.AthenaQuery

src/sagemaker/feature_store/feature_group.py

@@ -759,8 +759,8 @@ def load_feature_definitions(
         """Load feature definitions from a Pandas DataFrame.
 
         Column name is used as feature name. Feature type is inferred from the dtype
-        of the column. Dtype int_, int8, int16, int32, int64, uint8, uint16, uint32
-        and uint64 are mapped to Integral feature type. Dtype float_, float16, float32
+        of the column. Dtype :literal:`int_`, int8, int16, int32, int64, uint8, uint16, uint32
+        and uint64 are mapped to Integral feature type. Dtype :literal:`float_`, float16, float32
         and float64 are mapped to Fractional feature type. string dtype is mapped to
         String feature type.