Updated for possible Saxon installation via Homebrew.

  * installation.html: Saxon can be used for document generation.
      Graphviz is needed for diagram generation. Noted options
      when setting $SAXON.
  * saxon-installation.html: noted that Homebrew can install Saxon
      (and Graphviz).

installation.html

@@ -26,7 +26,7 @@ <h2>Prerequisites</h2>
 
 <li><a href="https://www.saxonica.com/" target="_blank" rel="noopener
 noreferrer">Saxon HE</a> (an XSLT processor, version 12 known to
-work, for code generation)
+work, for code and document generation)
 
 <li><a href="https://github.com/simonjwright/xia" target="_blank"
 rel="noopener noreferrer">XIA</a> (XPath in Ada library, for UML
@@ -41,7 +41,10 @@ <h2>Prerequisites</h2>
 
 <li><a href="https://github.com/simonjwright/scripted_testing"
 target="_blank" rel="noopener noreferrer">Scripted Testing</a>,
-likewise.
+likewise
+
+<li><a href="https://www.graphviz.org" target="_blank" rel="noopener
+noreferrer">Graphviz</a>, for diagram generation.
 
 </ul>
 
@@ -155,7 +158,8 @@ <h2>Environment variables</h2>
 <td>$COLDFRAME/models
 
 <tr><td>SAXON
-<td>How to run Saxon. Shouldn't need to be overridden.
+<td>How to run Saxon. Shouldn't need to be overridden, but
+see <a href="saxon-installation.html">here</a>.
 <td>$JAVA -cp $SAXON_CLASSPATH $SAXON_MAIN
 
 <tr><td>SAXON_CLASSPATH

saxon-installation.html

@@ -7,7 +7,13 @@
 
 <h1>ColdFrame: Saxon installation</h1>
 
-<p>We
+<p>If you're on a Mac using <a href="https://brew.sh">Homebrew</a>,
+just <tt>brew install saxon</tt> (and, if you haven't
+already, <tt>brew install graphviz</tt>): set the environment
+variable <tt>SAXON</tt> to <tt>saxon</tt> (you could make this
+permanent in ColdFrame's <tt>Makefile.inc</tt>).
+
+<p>Otherwise, we
 need <a href="https://www.saxonica.com/products/PD12/SaxonJ-HE.pdf">Saxon
 HE for Java</a> (Home Edition - paid-for versions are available, but
 may need a different invocation).