docs: don't use <tag> docbook elements

gtk/gtkapplicationwindow.c

@@ -111,16 +111,16 @@
  * ]|
  *
  * The XML format understood by #GtkBuilder for #GMenuModel consists
- * of a toplevel <tag class="starttag">menu</tag> element, which contains
- * one or more <tag class="starttag">item</tag> elements. Each
- * <tag class="starttag">item</tag> element contains
- * <tag class="starttag">attribute</tag> and <tag class="starttag">link</tag>
+ * of a toplevel `&lt;menu&gt;` element, which contains
+ * one or more `&lt;item&gt;` elements. Each
+ * `&lt;item&gt;` element contains
+ * `&lt;attribute&gt;` and `&lt;link&gt;`
  * elements with a mandatory name attribute.
- * <tag class="starttag">link</tag> elements have the same content
- * model as <tag class="starttag">menu</tag>.
+ * `&lt;link&gt;` elements have the same content
+ * model as `&lt;menu&gt;`.
  *
  * Attribute values can be translated using gettext, like other #GtkBuilder
- * content. <tag class="starttag">attribute</tag> elements can be marked for
+ * content. `&lt;attribute&gt;` elements can be marked for
  * translation with a <literal>translatable="yes"</literal> attribute.
  * It is also possible to specify message context and translator comments,
  * using the context and comments attributes. To make use of this, the

gtk/gtklabel.c

@@ -200,11 +200,12 @@
  *
  * Since 2.18, GTK+ supports markup for clickable hyperlinks in addition
  * to regular Pango markup. The markup for links is borrowed from HTML, using the
- * <tag>a</tag> with href and title attributes. GTK+ renders links similar to the
+ * `&lt;a&gt;` with href and title attributes. GTK+ renders links similar to the
  * way they appear in web browsers, with colored, underlined text. The title
  * attribute is displayed as a tooltip on the link.
  *
  * An example looks like this:
+ *
  * |[<!-- language="C" -->
  * gtk_label_set_markup (label, "Go to the <a href="http://www.gtk.org" title="&lt;i&gt;Our&lt;/i&gt; website">GTK+ website</a> for more...");
  * ]|

gtk/gtkoverlay.c

@@ -50,7 +50,7 @@
  *
  * The GtkOverlay implementation of the GtkBuildable interface
  * supports placing a child as an overlay by specifying "overlay" as
- * the "type" attribute of a <tag class="starttag">child</tag> element.
+ * the "type" attribute of a `&lt;child&gt;` element.
  */
 
 struct _GtkOverlayPrivate

gtk/gtkwindow.c

@@ -92,8 +92,8 @@
  * ## GtkWindow as GtkBuildable
  *
  * The GtkWindow implementation of the GtkBuildable interface supports a
- * custom <tag class="starttag">accel-groups</tag> element, which supports
- * any number of <tag class="starttag">group</tag> elements representing the
+ * custom `&lt;accel-groups&gt;` element, which supports
+ * any number of `&lt;group&gt;` elements representing the
  * #GtkAccelGroup objects you want to add to your window (synonymous with
  * gtk_window_add_accel_group().
  *
@@ -112,7 +112,7 @@
  * 
  * The GtkWindow implementation of the GtkBuildable interface
  * supports setting a child as the titlebar by specifying "titlebar" as
- * the "type" attribute of a <tag class="starttag">child</tag> element.
+ * the "type" attribute of a `&lt;child&gt;` element.
  */
 
 #define MNEMONICS_DELAY 300 /* ms */