updating whatsnew docs

Author: ArkadeepAdhikari

doc/source/user_guide/indexing.rst

@@ -676,7 +676,7 @@ Current behavior
    KeyError in the future, you can use .reindex() as an alternative.
 
    See the documentation here:
-   :ref:`deprecate loc reindex for list-likes <indexing.list_with_missing_labels_deprecated>`
+   :ref:`deprecate loc reindex for list-likes <indexing>`
 
    Out[4]:
    1    2.0

doc/source/whatsnew/v0.15.0.rst

@@ -852,7 +852,7 @@ Other notable API changes:
      A value is trying to be set on a copy of a slice from a DataFrame.
      Try using .loc[row_indexer,col_indexer] = value instead
 
-     See the caveats in the documentation :ref:`Indexing and Selecting data<indexing>`
+     See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
 
 - ``merge``, ``DataFrame.merge``, and ``ordered_merge`` now return the same type
   as the ``left`` argument (:issue:`7737`).

doc/source/whatsnew/v0.21.0.rst

@@ -470,7 +470,7 @@ Current behavior
    KeyError in the future, you can use .reindex() as an alternative.
 
    See the documentation here:
-   :ref:`Indexing and Selecting data<indexing>`
+   :ref:`Indexing and Selecting Data<indexing>`
 
    Out[4]:
    1    2.0