Docs: use sentence case for headers (#8914)

Co-authored-by: Andrew Murray <[email protected]>

Author: hugovk

Tests/README.rst

@@ -1,4 +1,4 @@
-Pillow Tests
+Pillow tests
 ============
 
 Test scripts are named ``test_xxx.py``. Helper classes and functions can be found in ``helper.py``.

docs/PIL.rst

@@ -1,66 +1,66 @@
-PIL Package (autodoc of remaining modules)
+PIL package (autodoc of remaining modules)
 ==========================================
 
 Reference for modules whose documentation has not yet been ported or written
 can be found here.
 
-:mod:`PIL` Module
+:mod:`PIL` module
 -----------------
 
 .. py:module:: PIL
 
 .. autoexception:: UnidentifiedImageError
     :show-inheritance:
 
-:mod:`~PIL.BdfFontFile` Module
+:mod:`~PIL.BdfFontFile` module
 ------------------------------
 
 .. automodule:: PIL.BdfFontFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.ContainerIO` Module
+:mod:`~PIL.ContainerIO` module
 ------------------------------
 
 .. automodule:: PIL.ContainerIO
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.FontFile` Module
+:mod:`~PIL.FontFile` module
 ---------------------------
 
 .. automodule:: PIL.FontFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.GdImageFile` Module
+:mod:`~PIL.GdImageFile` module
 ------------------------------
 
 .. automodule:: PIL.GdImageFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.GimpGradientFile` Module
+:mod:`~PIL.GimpGradientFile` module
 -----------------------------------
 
 .. automodule:: PIL.GimpGradientFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.GimpPaletteFile` Module
+:mod:`~PIL.GimpPaletteFile` module
 ----------------------------------
 
 .. automodule:: PIL.GimpPaletteFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.ImageDraw2` Module
+:mod:`~PIL.ImageDraw2` module
 -----------------------------
 
 .. automodule:: PIL.ImageDraw2
@@ -69,31 +69,31 @@ can be found here.
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.ImageMode` Module
+:mod:`~PIL.ImageMode` module
 ----------------------------
 
 .. automodule:: PIL.ImageMode
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.PaletteFile` Module
+:mod:`~PIL.PaletteFile` module
 ------------------------------
 
 .. automodule:: PIL.PaletteFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.PcfFontFile` Module
+:mod:`~PIL.PcfFontFile` module
 ------------------------------
 
 .. automodule:: PIL.PcfFontFile
     :members:
     :undoc-members:
     :show-inheritance:
 
-:class:`.PngImagePlugin.iTXt` Class
+:class:`.PngImagePlugin.iTXt` class
 -----------------------------------
 
 .. autoclass:: PIL.PngImagePlugin.iTXt
@@ -107,7 +107,7 @@ can be found here.
         :param lang: language code
         :param tkey: UTF-8 version of the key name
 
-:class:`.PngImagePlugin.PngInfo` Class
+:class:`.PngImagePlugin.PngInfo` class
 --------------------------------------
 
 .. autoclass:: PIL.PngImagePlugin.PngInfo
@@ -116,15 +116,15 @@ can be found here.
     :show-inheritance:
 
 
-:mod:`~PIL.TarIO` Module
+:mod:`~PIL.TarIO` module
 ------------------------
 
 .. automodule:: PIL.TarIO
     :members:
     :undoc-members:
     :show-inheritance:
 
-:mod:`~PIL.WalImageFile` Module
+:mod:`~PIL.WalImageFile` module
 -------------------------------
 
 .. automodule:: PIL.WalImageFile

docs/deprecations.rst

@@ -155,7 +155,7 @@ JpegImageFile.huffman_ac and JpegImageFile.huffman_dc
 The ``huffman_ac`` and ``huffman_dc`` dictionaries on JPEG images were unused. They
 have been deprecated, and will be removed in Pillow 12 (2025-10-15).
 
-Specific WebP Feature Checks
+Specific WebP feature checks
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 .. deprecated:: 11.0.0

docs/handbook/concepts.rst

@@ -84,7 +84,7 @@ pixels.
 
 .. _coordinate-system:
 
-Coordinate System
+Coordinate system
 -----------------
 
 The Python Imaging Library uses a Cartesian pixel coordinate system, with (0,0)

docs/handbook/image-file-formats.rst

@@ -1222,7 +1222,7 @@ numbers are returned as a tuple of ``(numerator, denominator)``.
 
     .. deprecated:: 3.0.0
 
-Reading Multi-frame TIFF Images
+Reading multi-frame TIFF images
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The TIFF loader supports the :py:meth:`~PIL.Image.Image.seek` and
@@ -1664,7 +1664,7 @@ The :py:meth:`~PIL.Image.open` method sets the following
     Transparency color index. This key is omitted if the image is not
     transparent.
 
-XV Thumbnails
+XV thumbnails
 ^^^^^^^^^^^^^
 
 Pillow can read XV thumbnail files.

docs/handbook/overview.rst

@@ -13,7 +13,7 @@ processing tool.
 
 Let’s look at a few possible uses of this library.
 
-Image Archives
+Image archives
 --------------
 
 The Python Imaging Library is ideal for image archival and batch processing
@@ -24,7 +24,7 @@ The current version identifies and reads a large number of formats. Write
 support is intentionally restricted to the most commonly used interchange and
 presentation formats.
 
-Image Display
+Image display
 -------------
 
 The current release includes Tk :py:class:`~PIL.ImageTk.PhotoImage` and
@@ -36,7 +36,7 @@ support.
 For debugging, there’s also a :py:meth:`~PIL.Image.Image.show` method which saves an image to
 disk, and calls an external display utility.
 
-Image Processing
+Image processing
 ----------------
 
 The library contains basic image processing functionality, including point operations, filtering with a set of built-in convolution kernels, and colour space conversions.

docs/handbook/tutorial.rst

@@ -122,7 +122,7 @@ This means that opening an image file is a fast operation, which is independent
 of the file size and compression type. Here’s a simple script to quickly
 identify a set of image files:
 
-Identify Image Files
+Identify image files
 ^^^^^^^^^^^^^^^^^^^^
 
 ::
@@ -399,7 +399,7 @@ Applying filters
 .. image:: enhanced_hopper.webp
     :align: center
 
-Point Operations
+Point operations
 ^^^^^^^^^^^^^^^^
 
 The :py:meth:`~PIL.Image.Image.point` method can be used to translate the pixel

docs/handbook/writing-your-own-image-plugin.rst

@@ -1,6 +1,6 @@
 .. _image-plugins:
 
-Writing Your Own Image Plugin
+Writing your own image plugin
 =============================
 
 Pillow uses a plugin model which allows you to add your own
@@ -329,7 +329,7 @@ The fields are used as follows:
 
 .. _file-codecs:
 
-Writing Your Own File Codec in C
+Writing your own file codec in C
 ================================
 
 There are 3 stages in a file codec's lifetime:
@@ -414,7 +414,7 @@ memory and release any resources from external libraries.
 
 .. _file-codecs-py:
 
-Writing Your Own File Codec in Python
+Writing your own file codec in Python
 =====================================
 
 Python file decoders and encoders should derive from

docs/installation.rst

@@ -3,27 +3,27 @@
 Installation
 ============
 
-Basic Installation
+Basic installation
 ------------------
 
 .. Note:: This section has moved to :ref:`basic-installation`. Please update references accordingly.
 
-Python Support
+Python support
 --------------
 
 .. Note:: This section has moved to :ref:`python-support`. Please update references accordingly.
 
-Platform Support
+Platform support
 ----------------
 
 .. Note:: This section has moved to :ref:`platform-support`. Please update references accordingly.
 
-Building From Source
+Building from source
 --------------------
 
 .. Note:: This section has moved to :ref:`building-from-source`. Please update references accordingly.
 
-Old Versions
+Old versions
 ------------
 
 .. Note:: This section has moved to :ref:`old-versions`. Please update references accordingly.

docs/installation/basic-installation.rst

@@ -8,7 +8,7 @@
 
 .. _basic-installation:
 
-Basic Installation
+Basic installation
 ==================
 
 .. note::