doc(coq): document coqdoc_flags in env stanza

Signed-off-by: Ali Caglayan <alizter@gmail.com>

doc/coq.rst

@@ -788,3 +788,19 @@ configuration. These are:
 
 See :doc:`concepts/variables` for more information on variables supported by
 Dune.
+
+
+.. _coq-env:
+
+Coq Environment Fields
+----------------------
+
+The :ref:`dune-env` stanza has a ``(coq <coq_fields>)`` field with the following
+values for ``<coq_fields>``:
+
+- ``(flags <flags>)``: The default flags passed to ``coqc``. The default value
+  is ``-q``. Values set here become the ``:standard`` value in the
+  ``(coq.theory (flags <flags>))`` field. 
+- ``(coqdoc_flags <flags>)``: The default flags passed to ``coqdoc``. The default
+  value is ``--toc``. Values set here become the ``:standard`` value in the
+  ``(coq.theory (coqdoc_flags <flags>))`` field.

doc/stanzas/env.rst

@@ -62,7 +62,7 @@ Fields supported in ``<settings>`` are:
 - ``(odoc <fields>)`` allows passing options to ``odoc``. See
   :ref:`odoc-options` for more details.
 
-- ``(coq (flags <flags>))`` allows passing options to Coq. See :ref:`coq-theory`
+- ``(coq <coq_fields>)`` allow passing options to Coq. See :ref:`coq-env`
   for more details.
 
 - ``(formatting <settings>)`` allows the user to set auto-formatting in the