DOC: fix mask/where docstring alignment note (#61781)

The explanatory paragraph wrongly said that alignment is between
`other` and `cond`.  It is between *self* and `cond`; values fall
back to *self* for mis-aligned positions.  Update both generic
docstring templates so all Series/DataFrame variants inherit the
correct wording.

Closes #61781

Signed-off-by: Abhay Singh <[email protected]>

Author: abhaypsingh

pandas/core/generic.py

@@ -9946,9 +9946,9 @@ def where(
         The {name} method is an application of the if-then idiom. For each
         element in the caller, if ``cond`` is ``{cond}`` the
         element is used; otherwise the corresponding element from
-        ``other`` is used. If the axis of ``other`` does not align with axis of
-        ``cond`` {klass}, the values of ``cond`` on misaligned index positions
-        will be filled with {cond_rev}.
+        ``other`` is used. If the axis of ``self`` does not align with axis of
+        ``cond``, misaligned index positions will be filled with the original value
+        from ``self``.
 
         The signature for :func:`Series.where` or
         :func:`DataFrame.where` differs from :func:`numpy.where`.