doc/dev: link to Dot User's Manual

Add a link to the Dot User's Manual for Graphviz diagrams.

Signed-off-by: Zac Dover <zac.dover@gmail.com>

diff --git a/doc/dev/documenting.rst b/doc/dev/documenting.rst
index f84342bc715c9dbed7507319150f0a17d8ad11b3..1b9468a5012c6e81f47fda8a072e868a115ec3fe 100644 (file)
--- a/doc/dev/documenting.rst
+++ b/doc/dev/documenting.rst
@@ -88,6 +88,10 @@ separate file, like this::
 
   .. graphviz:: myfile.dot
 
+See the `Dot User's Manual <https://www.graphviz.org/pdf/dotguide.pdf>`_ by
+Emden R. Gansner, Eleftherios Koutsofios, and Stephen North for examples of
+digraphs. This is especially useful if this is your first time encountering
+GraphViz.
 
 Ditaa
 -----