[gtk/ebassi/gidocgen] doc: Port GtkConstraint to the new format

[Emmanuele Bassi <ebassi src gnome org>]

commit daec45d81bd8cadff960d9a162a14fc0830a7a9a
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sun Feb 14 18:00:00 2021 +0000

    doc: Port GtkConstraint to the new format

 gtk/gtkconstraint.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/gtk/gtkconstraint.c b/gtk/gtkconstraint.c
index 8bef75eced..d3806b9737 100644
--- a/gtk/gtkconstraint.c
+++ b/gtk/gtkconstraint.c
@@ -22,19 +22,20 @@
  * @Title: GtkConstraint
  * @Short_description: The description of a constraint
  *
- * #GtkConstraint describes a constraint between an attribute on a widget
+ * `GtkConstraint` describes a constraint between an attribute on a widget
  * and another attribute on another widget, expressed as a linear equation
  * like:
  *
- * |[
+ * ```
  *   target.attr1 = source.attr2 × multiplier + constant
- * ]|
+ * ```
  *
- * Each #GtkConstraint is part of a system that will be solved by a
- * #GtkConstraintLayout in order to allocate and position each child widget.
+ * Each `GtkConstraint` is part of a system that will be solved by a
+ * [class@Gtk.ConstraintLayout] in order to allocate and position each
+ * child widget or guide.
  *
- * The source and target widgets, as well as their attributes, of a
- * #GtkConstraint instance are immutable after creation.
+ * The source and target, as well as their attributes, of a `GtkConstraint`
+ * instance are immutable after creation.
  */
 
 #include "config.h"