DOC: Remove ambiguity in fill_value documentation (#33788)

Author: bharatr21

pandas/core/ops/docstrings.py

@@ -399,7 +399,7 @@ def _make_flex_doc(op_name, typ):
 Return {desc} of series and other, element-wise (binary operator `{op_name}`).
 
 Equivalent to ``{equiv}``, but with support to substitute a fill_value for
-missing data in one of the inputs.
+missing data in either one of the inputs.
 
 Parameters
 ----------
@@ -408,7 +408,7 @@ def _make_flex_doc(op_name, typ):
     Fill existing missing (NaN) values, and any new element needed for
     successful Series alignment, with this value before computation.
     If data in both corresponding Series locations is missing
-    the result will be missing.
+    the result of filling (at that location) will be missing.
 level : int or name
     Broadcast across a level, matching Index values on the
     passed MultiIndex level.