Update doc dependencies in the doc itself

We changed themes a while back, but the hacking.rst file still mentionned the old one.

Signed-off-by: Ambre Austen Suhamy <[email protected]>

doc/hacking.rst

@@ -342,7 +342,7 @@ Documentation
 User documentation lives in the ``./doc`` directory.
 
 In order to build the user documentation, you must install python-sphinx_,
-sphinx_rtd_theme_ and sphinx-copybutton_.
+sphinx-design_, myst-parser_, sphinx-copybutton_, and furo_.
 
 Build the documentation with
 
@@ -357,9 +357,11 @@ For automatically updated builds, you can install sphinx-autobuild_, and run
    $ make livedoc
 
 .. _python-sphinx: http://www.sphinx-doc.org/en/master/usage/installation.html
-.. _sphinx_rtd_theme: https://sphinx-rtd-theme.readthedocs.io/en/stable/
+.. _sphinx-design: https://sphinx-design.readthedocs.io/en/latest/index.html
+.. _myst-parser: https://myst-parser.readthedocs.io/en/latest/
 .. _sphinx-autobuild: https://pypi.org/project/sphinx-autobuild/
 .. _sphinx-copybutton: https://sphinx-copybutton.readthedocs.io/en/latest/index.html
+.. _furo: https://sphinx-themes.org/sample-sites/furo/
 .. _dune-release: https://github.com/ocamllabs/dune-release
 
 Nix users may drop into a development shell with the necessary dependencies for