Consistent header underlines

docs/installation/basic-installation.rst

@@ -1,7 +1,7 @@
 .. _basic-installation:
 
 Basic Installation
-------------------
+==================
 
 .. note::
 

docs/installation/building-from-source.rst

@@ -7,12 +7,12 @@
 .. _building-from-source:
 
 Building From Source
---------------------
+====================
 
 .. _external-libraries:
 
 External Libraries
-^^^^^^^^^^^^^^^^^^
+------------------
 
 .. note::
 
@@ -227,7 +227,7 @@ Many of Pillow's features require external libraries:
     This has been tested within the Termux app on ChromeOS, on x86.
 
 Installing
-^^^^^^^^^^
+----------
 
 Once you have installed the prerequisites, to install Pillow from the source
 code on PyPI, run::
@@ -262,7 +262,7 @@ After navigating to the Pillow directory, run::
 .. _compressed archive from PyPI: https://pypi.org/project/pillow/#files
 
 Build Options
-"""""""""""""
+^^^^^^^^^^^^^
 
 * Environment variable: ``MAX_CONCURRENCY=n``. Pillow can use
   multiprocessing to build the extension. Setting ``MAX_CONCURRENCY``

docs/installation/platform-support.rst

@@ -1,7 +1,7 @@
 .. _platform-support:
 
 Platform Support
-----------------
+================
 
 Current platform support for Pillow. Binary distributions are
 contributed for each release on a volunteer basis, but the source
@@ -10,7 +10,7 @@ general, we aim to support all current versions of Linux, macOS, and
 Windows.
 
 Continuous Integration Targets
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+------------------------------
 
 These platforms are built and tested for every change.
 
@@ -66,7 +66,7 @@ These platforms are built and tested for every change.
 
 
 Other Platforms
-^^^^^^^^^^^^^^^
+---------------
 
 These platforms have been reported to work at the versions mentioned.
 

docs/installation/python-support.rst

@@ -1,7 +1,7 @@
 .. _python-support:
 
 Python Support
---------------
+==============
 
 Pillow supports these Python versions.