DOC: Fix title capitalization in documentation files (#32550)

doc/source/whatsnew/v0.12.0.rst

@@ -133,9 +133,9 @@ API changes
     to be inserted if ``True``, default is ``False`` (same as prior to 0.12) (:issue:`3679`)
   - Implement ``__nonzero__`` for ``NDFrame`` objects (:issue:`3691`, :issue:`3696`)
 
-  - IO api
+  - IO API
 
-    - added top-level function ``read_excel`` to replace the following,
+    - Added top-level function ``read_excel`` to replace the following,
       The original API is deprecated and will be removed in a future version
 
       .. code-block:: python
@@ -153,7 +153,7 @@ API changes
 
          pd.read_excel("path_to_file.xls", "Sheet1", index_col=None, na_values=["NA"])
 
-    - added top-level function ``read_sql`` that is equivalent to the following
+    - Added top-level function ``read_sql`` that is equivalent to the following
 
       .. code-block:: python
 
@@ -482,11 +482,11 @@ Bug fixes
 
   - ``HDFStore``
 
-    - will retain index attributes (freq,tz,name) on recreation (:issue:`3499`)
-    - will warn with a ``AttributeConflictWarning`` if you are attempting to append
+    - Will retain index attributes (freq,tz,name) on recreation (:issue:`3499`)
+    - Will warn with a ``AttributeConflictWarning`` if you are attempting to append
       an index with a different frequency than the existing, or attempting
       to append an index with a different name than the existing
-    - support datelike columns with a timezone as data_columns (:issue:`2852`)
+    - Support datelike columns with a timezone as data_columns (:issue:`2852`)
 
   - Non-unique index support clarified (:issue:`3468`).
 

doc/source/whatsnew/v0.25.0.rst

@@ -551,7 +551,7 @@ with :attr:`numpy.nan` in the case of an empty :class:`DataFrame` (:issue:`26397
 ``__str__`` methods now call ``__repr__`` rather than vice versa
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-pandas has until now mostly defined string representations in a pandas objects'
+Pandas has until now mostly defined string representations in a pandas objects'
 ``__str__``/``__unicode__``/``__bytes__`` methods, and called ``__str__`` from the ``__repr__``
 method, if a specific ``__repr__`` method is not found. This is not needed for Python3.
 In pandas 0.25, the string representations of pandas objects are now generally

doc/source/whatsnew/v1.2.0.rst

@@ -64,7 +64,7 @@ By default, duplicates continue to be allowed.
     label
     a        [0, 1]
 
-pandas will propagate the ``allows_duplicate_labels`` property through many operations.
+Pandas will propagate the ``allows_duplicate_labels`` property through many operations.
 
 .. code-block:: ipython
 

doc/source/whatsnew/v3.0.0.rst

@@ -16,12 +16,12 @@ Enhancements
 
 .. _whatsnew_300.enhancements.enhancement1:
 
-enhancement1
+Enhancement1
 ^^^^^^^^^^^^
 
 .. _whatsnew_300.enhancements.enhancement2:
 
-enhancement2
+Enhancement2
 ^^^^^^^^^^^^
 
 .. _whatsnew_300.enhancements.other:
@@ -269,7 +269,7 @@ This change also applies to :meth:`.DataFrameGroupBy.value_counts`. Here, there
 Increased minimum version for Python
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-pandas 3.0.0 supports Python 3.10 and higher.
+Pandas 3.0.0 supports Python 3.10 and higher.
 
 Increased minimum versions for dependencies
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -305,7 +305,7 @@ See :ref:`install.dependencies` and :ref:`install.optional_dependencies` for mor
 ``pytz`` now an optional dependency
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-pandas now uses :py:mod:`zoneinfo` from the standard library as the default timezone implementation when passing a timezone
+Pandas now uses :py:mod:`zoneinfo` from the standard library as the default timezone implementation when passing a timezone
 string to various methods. (:issue:`34916`)
 
 *Old behavior:*