Add further indentation to variable lists to distinguish groups.

This was an regression introduced by the new styles that affects
readability of nested variables lists (e.g. on the message protocol
page). This brings the look more in line with the previous documentation
styles and should help with readability.

media/css/main.css

@@ -941,6 +941,21 @@ code,
     font-weight: 300;
 }
 
+#docContent .VARIABLELIST dt,
+#docContent .variablelist dt {
+    font-family: monospace;
+    font-weight: 300;
+}
+
+#docContent .variablelist dd {
+    margin-top: 1rem;
+}
+
+#docContent .VARIABLELIST dd,
+#docContent .variablelist dd {
+    margin-inline-start: 2rem;
+}
+
 #docContent ul.itemizedlist {
     margin-left: 2.5rem;
 }