[5.1.x] Used :pypi: role in docs where appropriate.

Backport of 304d256674 from main.

docs/ref/contrib/gis/geoip2.txt

@@ -5,8 +5,8 @@ Geolocation with GeoIP2
 .. module:: django.contrib.gis.geoip2
     :synopsis: Python interface for MaxMind's GeoIP2 databases.
 
-The :class:`GeoIP2` object is a wrapper for the `MaxMind geoip2 Python
-library`__. [#]_
+The :class:`GeoIP2` object is a wrapper for the :pypi:`MaxMind geoip2 Python
+library <geoip2>`. [#]_
 
 In order to perform IP-based geolocation, the :class:`GeoIP2` object requires
 the :pypi:`geoip2` Python package and the GeoIP ``Country`` and/or ``City``
@@ -18,7 +18,6 @@ the :setting:`GEOIP_PATH` setting.
 Additionally, it is recommended to install the `libmaxminddb C library`__, so
 that ``geoip2`` can leverage the C library's faster speed.
 
-__ https://geoip2.readthedocs.io/
 __ https://dev.maxmind.com/geoip/geolite2-free-geolocation-data
 __ https://db-ip.com/db/lite.php
 __ https://github.com/maxmind/libmaxminddb/

docs/ref/forms/fields.txt

@@ -813,11 +813,11 @@ For each field, we describe the default widget used if you don't specify
     * Error message keys: ``required``, ``invalid``, ``missing``, ``empty``,
       ``invalid_image``
 
-    Using an ``ImageField`` requires that `Pillow`_ is installed with support
-    for the image formats you use. If you encounter a ``corrupt image`` error
-    when you upload an image, it usually means that Pillow doesn't understand
-    its format. To fix this, install the appropriate library and reinstall
-    Pillow.
+    Using an ``ImageField`` requires that :pypi:`pillow` is installed with
+    support for the image formats you use. If you encounter a ``corrupt image``
+    error when you upload an image, it usually means that Pillow doesn't
+    understand its format. To fix this, install the appropriate library and
+    reinstall Pillow.
 
     When you use an ``ImageField`` on a form, you must also remember to
     :ref:`bind the file data to the form <binding-uploaded-files>`.
@@ -863,7 +863,6 @@ For each field, we describe the default widget used if you don't specify
     image's content type if Pillow can determine it, otherwise it will be set
     to ``None``.
 
-.. _Pillow: https://pillow.readthedocs.io/en/latest/
 .. _Image: https://pillow.readthedocs.io/en/latest/reference/Image.html
 
 ``IntegerField``

docs/ref/models/fields.txt

@@ -12,8 +12,8 @@ This document contains all the API references of :class:`Field` including the
 
 .. seealso::
 
-    If the built-in fields don't do the trick, you can try `django-localflavor
-    <https://github.com/django/django-localflavor>`_ (`documentation
+    If the built-in fields don't do the trick, you can try
+    :pypi:`django-localflavor` (`documentation
     <https://django-localflavor.readthedocs.io/>`_), which contains assorted
     pieces of code that are useful for particular countries and cultures.
 
@@ -1369,9 +1369,7 @@ following optional arguments:
     Name of a model field which is auto-populated with the width of the image
     each time an image object is set.
 
-Requires the `Pillow`_ library.
-
-.. _Pillow: https://pillow.readthedocs.io/en/latest/
+Requires the :pypi:`pillow` library.
 
 :class:`ImageField` instances are created in your database as ``varchar``
 columns with a default max length of 100 characters. As with other fields, you