docs: More syntax fixes

The syntax for interface links is [iface@...], not
[interface@...].

gdk/gdkpopuplayout.c

@@ -26,7 +26,7 @@
  * GdkPopupLayout:
  *
  * The `GdkPopupLayout` struct contains information that is
- * necessary position a [interface@Gdk.Popup] relative to its parent.
+ * necessary position a [iface@Gdk.Popup] relative to its parent.
  *
  * The positioning requires a negotiation with the windowing system,
  * since it depends on external constraints, such as the position of

gdk/wayland/gdksurface-wayland.c

@@ -58,7 +58,7 @@
  *
  * The Wayland implementation of `GdkToplevel`.
  *
- * Beyond the [interface@Gdk.Toplevel] API, the Wayland implementation
+ * Beyond the [iface@Gdk.Toplevel] API, the Wayland implementation
  * has API to set up cross-process parent-child relationships between
  * surfaces with [method@GdkWayland.WaylandToplevel.export_handle] and
  * [method@GdkWayland.WaylandToplevel.set_transient_for_exported].

gtk/gtkbuilderscope.h

@@ -41,7 +41,7 @@ G_DECLARE_INTERFACE (GtkBuilderScope, gtk_builder_scope, GTK, BUILDER_SCOPE, GOb
  * The list of flags that can be passed to gtk_builder_create_closure().
  *
  * New values may be added in the future for new features, so external
- * implementations of [interface@Gtk.BuilderScope] should test the flags
+ * implementations of [iface@Gtk.BuilderScope] should test the flags
  * for unknown values and raise a %GTK_BUILDER_ERROR_INVALID_ATTRIBUTE error
  * when they encounter one.
  */

gtk/gtkcheckbutton.c

@@ -919,7 +919,7 @@ gtk_check_button_set_label (GtkCheckButton *self,
  *
  * Setting up groups in a cycle leads to undefined behavior.
  *
- * Note that the same effect can be achieved via the [interface@Gtk.Actionable]
+ * Note that the same effect can be achieved via the [iface@Gtk.Actionable]
  * API, by using the same action with parameter type and state type 's'
  * for all buttons in the group, and giving each button its own target
  * value.

gtk/gtkcombobox.c

@@ -58,7 +58,7 @@
  * is specified in the form of a tree model, and the display of the choices
  * can be adapted to the data in the model by using cell renderers, as you
  * would in a tree view. This is possible since `GtkComboBox` implements the
- * [interface@Gtk.CellLayout] interface. The tree model holding the valid
+ * [iface@Gtk.CellLayout] interface. The tree model holding the valid
  * choices is not restricted to a flat list, it can be a real tree, and the
  * popup will reflect the tree structure.
  *

gtk/gtkcomboboxtext.c

@@ -52,7 +52,7 @@
  * using [method@Gtk.ComboBoxText.get_active_text].
  *
  * You should not call [method@Gtk.ComboBox.set_model] or attempt to pack more
- * cells into this combo box via its [interface@Gtk.CellLayout] interface.
+ * cells into this combo box via its [iface@Gtk.CellLayout] interface.
  *
  * # GtkComboBoxText as GtkBuildable
  *

gtk/gtktogglebutton.c

@@ -478,7 +478,7 @@ gtk_toggle_button_toggled (GtkToggleButton *toggle_button)
  *
  * Setting up groups in a cycle leads to undefined behavior.
  *
- * Note that the same effect can be achieved via the [interface@Gtk.Actionable]
+ * Note that the same effect can be achieved via the [iface@Gtk.Actionable]
  * API, by using the same action with parameter type and state type 's'
  * for all buttons in the group, and giving each button its own target
  * value.

gtk/gtktreesortable.h

@@ -37,7 +37,7 @@ G_BEGIN_DECLS
 /**
  * GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID:
  *
- * Uses the default sort function in a [interface@Gtk.TreeSortable].
+ * Uses the default sort function in a [iface@Gtk.TreeSortable].
  *
  * See also: [method@Gtk.TreeSortable.set_sort_column_id]
  */
@@ -46,7 +46,7 @@ G_BEGIN_DECLS
 /**
  * GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID:
  *
- * Disables sorting in a [interface@Gtk.TreeSortable].
+ * Disables sorting in a [iface@Gtk.TreeSortable].
  *
  * See also: [method@Gtk.TreeSortable.set_sort_column_id]
  */