updating whatsnew docs

Author: ArkadeepAdhikari

doc/source/getting_started/comparison/comparison_with_sql.rst

@@ -75,7 +75,7 @@ Filtering in SQL is done via a WHERE clause.
     LIMIT 5;
 
 DataFrames can be filtered in multiple ways; the most intuitive of which is using
-:ref:`boolean indexing <boolean.indexing>`.
+:ref:`Boolean Indexing <indexing.boolean_indexing>`.
 
 .. ipython:: python
 

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>`
+   :ref:`Indexing and Selecting Data <indexing.list_with_missing_labels_deprecated>`
 
    Out[4]:
    1    2.0

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.list_with_missing_labels_deprecated>`
 
    Out[4]:
    1    2.0