Merge pull request #2871 from webknjaz/maintenance/docs-pip-editable-…

…v21.1

Document that pip works with editable `setup.cfg`

changelog.d/2871.doc.rst

@@ -0,0 +1,4 @@
+Added a note to the docs that it is possible to install
+``setup.py``-less projects in editable mode with :doc:`pip v21.1+
+<pip:index>`, only having ``setup.cfg`` and ``pyproject.toml`` in
+project root -- by :user:`webknjaz`

docs/conf.py

@@ -171,3 +171,5 @@
 towncrier_draft_include_empty = False
 
 extensions += ['jaraco.tidelift']
+
+intersphinx_mapping['pip'] = 'https://pip.pypa.io/en/latest', None

docs/userguide/quickstart.rst

@@ -186,17 +186,18 @@ For more details, see :doc:`datafiles`
 
 Development mode
 ================
-``setuptools`` allows you to install a package without copying any files
-to your interpreter directory (e.g. the ``site-packages`` directory). This
-allows you to modify your source code and have the changes take effect without
-you having to rebuild and reinstall. This is currently incompatible with
-PEP 517 and therefore it requires a ``setup.py`` script with the following
-content::
 
-    import setuptools
-    setuptools.setup()
+.. tip::
+
+	Prior to :ref:`pip v21.1 <pip:v21-1>`, a ``setup.py`` script was
+	required to be compatible with development mode. With late
+	versions of pip, any project may be installed in this mode.
 
-Then::
+``setuptools`` allows you to install a package without copying any files
+to your interpreter directory (e.g. the ``site-packages`` directory).
+This allows you to modify your source code and have the changes take
+effect without you having to rebuild and reinstall.
+Here's how to do it::
 
     pip install --editable .