Add draft documentation (incomplete)

Author: jaraco

CHANGELOG.rst

@@ -1,3 +1,9 @@
+v3.4.0
+======
+
+* fix #181 - add support for projects built under setuptools declarative config
+  by way of the setuptools.finalize_distribution_options hook in Setuptools 42.
+
 * fix #305 - ensure the git file finder closes filedescriptors even when errors happen
 
 v3.3.3

README.rst

@@ -13,6 +13,29 @@ It also handles file finders for the supported SCMs.
 .. image:: https://tidelift.com/badges/github/pypa/setuptools_scm
    :target: https://tidelift.com/subscription/pkg/pypi-setuptools_scm?utm_source=pypi-setuptools_scm&utm_medium=readme
 
+``pyproject.toml`` usage
+------------------------
+
+The preferred way to configure ``setuptools_scm`` is to author
+settings in a ``tool.setuptools_scm`` section of ``pyproject.toml``.
+
+This feature requires Setuptools 42 or later, released in Nov, 2019.
+If your project needs to support build from sdist on older versions
+of Setuptools, you will need to also implement the ``setup.py usage``
+for those legacy environments.
+
+First, ensure that ``setuptools_scm`` is present during the project's
+built step by specifying it as one of the build requirements.
+
+.. code:: ini
+
+    # pyproject.toml
+    [build-system]
+    requires = ["setuptools>=42", "wheel", "setuptools_scm>=3.4"]
+
+
+To enable version inference, add this section to your pyproject.toml
+
 ``setup.py`` usage
 ------------------