doc: tips: using sphinx-autobuild with hawkmoth

Fixes #87

doc/tips.rst

@@ -77,3 +77,16 @@ Your regular build will then use the generated file, and the documentation build
 will use the static file. The static file may be empty, or contain just the
 minimal types and macros to avoid compiler errors, or you can add full blown
 code documentation in the header stubs.
+
+Using sphinx-autobuild with Hawkmoth
+------------------------------------
+
+`sphinx-autobuild`_ is a handy tool to automatically rebuild Sphinx
+documentation when you modify the ``.rst`` files, with live-reload in the
+browser.
+
+It's possible to have it auto rebuild and live-reload source documentation on
+source code changes by adding ``--watch <source root>`` option to
+``sphinx-autobuild``, where ``<source root>`` matches :py:data:`hawkmoth_root`.
+
+.. _sphinx-autobuild: https://github.com/executablebooks/sphinx-autobuild