manual: develop: add the beginnings of a style guide

docs/manual/src/develop/docs.rst

@@ -64,3 +64,15 @@ At the moment, some of the URLs fail despite being valid, so this command is not
 .. _Sphinx: https://www.sphinx-doc.org/en/master/index.html
 .. _PDM: https://pdm.fming.dev/latest/
 .. _install PDM: https://pdm.fming.dev/latest/#installation
+
+
+Style guide
+-----------
+
+When writing documentation, please try to follow our style:
+
+* Only capitalise the first word of headings
+* Insert two blank lines before headings
+* Use ``.. note::`` and ``.. warning::`` sparingly, but where important details may otherwise be missed
+* Use an em-dash (---), which can be written as ``---`` in restructured text
+* Link to our official `GlasgowEmbedded <https://github.com/GlasgowEmbedded>`_ repositories where appropriate