pip install -e .[docs] for docs dependencies

docs/contributing.rst

@@ -91,7 +91,7 @@ You can build it locally by installing ``sphinx`` and ``sphinx_rtd_theme`` in yo
     source venv/bin/activate
 
     # Install the dependencies needed to build the docs
-    pip install sphinx sphinx_rtd_theme
+    pip install -e .[docs]
 
     # Now build the docs
     cd docs/
@@ -103,16 +103,14 @@ This will create the HTML version of the documentation in ``docs/_build/html``.
 
 Any time you make changes to a ``.rst`` file you can re-run ``make html`` to update the built documents, then refresh them in your browser.
 
-For added productivity, you can run Sphinx in auto-build mode. This will run a local webserver serving the docs that automatically rebuilds them and refreshes the page any time you hit save in your editor.
+For added productivity, you can use use `sphinx-autobuild <https://pypi.org/project/sphinx-autobuild/>`__ to run Sphinx in auto-build mode. This will run a local webserver serving the docs that automatically rebuilds them and refreshes the page any time you hit save in your editor.
 
-To enable auto-build mode, first install `sphinx-autobuild <https://pypi.org/project/sphinx-autobuild/>`__::
+``sphinx-autobuild`` will have been installed when you ran ``pip install -e .[docs]``. In your ``docs/`` directory you can start the server by running the following::
-
-    pip install sphinx-autobuild
-
-Now start the server by running::
 
     make livehtml
 
+Now browse to ``http://localhost:8000/`` to view the documentation. Any edits you make should be instantly relected in your browser.
+
 .. _contributing_release:
 
 Release process

setup.py

@@ -56,10 +56,7 @@ setup(
     """,
     setup_requires=["pytest-runner"],
     extras_require={
-        "docs": [
+        "docs": ["sphinx_rtd_theme", "sphinx-autobuild"],
-            "sphinx_rtd_theme",
-            "sphinx-autobuild",
-        ],
         "test": [
             "pytest==4.6.1",
             "pytest-asyncio==0.10.0",
@@ -67,7 +64,7 @@ setup(
             "beautifulsoup4==4.6.1",
             "asgiref==3.1.2",
         ]
-        + maybe_black
+        + maybe_black,
     },
     tests_require=["datasette[test]"],
     classifiers=[