Update doc/OnlineDocs/explanation/analysis/doe/guide.rst

Co-authored-by: John Siirola <jsiirola@users.noreply.github.com>

Author: slilonfe5

doc/OnlineDocs/explanation/analysis/doe/guide.rst

@@ -7,7 +7,7 @@ To use Pyomo.DoE, a user must implement a subclass of the :ref:`Parmest <parmest
 The subclass must have a ``get_labeled_model`` method which returns a Pyomo :class:`ConcreteModel`
 containing four Pyomo :class:`Suffix` components identifying the parts of the model used in
 MBDoE analysis. This is in line with the convention used in the parameter estimation tool,
-:ref:`Parmest <parmest>`. The four Pyomo ``Suffix`` components are:
+:ref:`Parmest <parmest>`. The four Pyomo :class:`Suffix` components are:
 
 * ``experiment_inputs`` - The experimental design decisions
 * ``experiment_outputs`` - The values measured during the experiment