doc: Added iloc dtype conversion behaviours

Author: zihengliao

pandas/core/indexing.py

@@ -182,6 +182,10 @@ def iloc(self) -> _iLocIndexer:
         ``.iloc`` will raise ``IndexError`` if a requested indexer is
         out-of-bounds, except *slice* indexers which allow out-of-bounds
         indexing (this conforms with python/numpy *slice* semantics).
+        
+        It is also worth noting, iloc converts all elements returned into the same 
+        pandas dtype and all numeric dtype conversions follow the numpy promotion 
+        rules.
 
         See more at :ref:`Selection by Position <indexing.integer>`.