docs: Bring the widget gallery back

We have all the images, lets put them to use.

docs/reference/gtk/gtk4.toml.in

@@ -68,6 +68,7 @@ content_files = [
   "wayland.md",
   "windows.md",
   "x11.md",
+  "visual_index.md",
 ]
 content_images = [
   "images/aboutdialog.png",

docs/reference/gtk/meson.build

@@ -24,6 +24,7 @@ expand_content_md_files = [
   'section-tree-widget.md',
   'section-list-widget.md',
   'question_index.md',
+  'visual_index.md'
 ]
 
 gtk4_toml = configure_file(input: 'gtk4.toml.in', output: 'gtk4.toml', configuration: toml_conf)

docs/reference/gtk/visual_index.md

@@ -0,0 +1,82 @@
+Title: Widget Gallery
+
+## Display widgets
+
+[![label](label.png)](class.Label.html)
+[![spinner](spinner.png)](class.Spinner.html)
+[![statusbar](statusbar.png)](class.Statusbar.html)
+[![levelbar](levelbar.png)](class.LevelBar.html)
+[![progressbar](progressbar.png)](class.ProgressBar.html)
+[![infobar](info-bar.png)](class.InfoBar.html)
+[![scrollbar](scrollbar.png)](class.Scrollbar.html)
+[![image](image.png)](class.Image.html)
+[![picture](picture.png)](class.Picture.html)
+[![separator](separator.png)](class.Separator.html)
+[![textview](multiline-text.png)](class.TextView.html)
+[![scale](scales.png)](class.Scale.html)
+[![calendar](calendar.png)](class.Calendar.html)
+[![glarea](glarea.png)](class.GLArea.html)
+[![drawingarea](drawingarea.png)](class.DrawingArea.html)
+[![video](video.png)](class.Video.html)
+
+## Buttons
+
+[![button](button.png)](class.Button.html)
+[![togglebutton](toggle-button.png)](class.ToggleButton.html)
+[![linkbutton](link-button.png)](class.LinkButton.html)
+[![checkbutton](check-button.png)](class.CheckButton.html)
+[![menubutton](menu-button.png)](class.MenuButton.html)
+[![lockbutton](lockbutton.png)](class.LockButton.html)
+[![volumebutton](volumebutton.png)](class.VolumeButton.html)
+[![switch](switch.png)](class.Switch.html)
+[![combobox](combo-box.png)](class.ComboBox.html)
+[![comboboxtext](combo-box-text.png)](class.ComboBoxText.html)
+[![dropdown](drop-down.png)](class.DropDown.html)
+[![colorbutton](color-button.png)](class.ColorButton.html)
+[![fontbutton](font-button.png)](class.FontButton.html)
+[![appchooserbutton](appchooserbutton.png)](class.AppChooserButton.html)
+
+## Entries
+
+[![entry](entry.png)](class.Entry.html)
+[![searchentry](search-entry.png)](class.SearchEntry.html)
+[![passwordentry](password-entry.png)](class.PasswordEntry.html)
+[![spinbutton](spinbutton.png)](class.SpinButton.html)
+[![editablelabel](editable-label.png)](class.EditableLabel.html)
+
+## Containers
+
+[![box](box.png)](class.Box.html)
+[![grid](grid.png)](class.Grid.html)
+[![centerbox](centerbox.png)](class.CenterBox.html)
+[![scrolledwindow](scrolledwindow.png)](class.ScrolledWindow.html)
+[![panes](panes.png)](class.Paned.html)
+[![frame](frame.png)](class.Frame.html)
+[![expander](expander.png)](class.Expander.html)
+[![searchbar](search-bar.png)](class.SearchBar.html)
+[![actionbar](action-bar.png)](class.ActionBar.html)
+[![headerbar](headerbar.png)](class.HeaderBar.html)
+[![notebook](notebook.png)](class.Notebook.html)
+[![listbox](list-box.png)](class.ListBox.html)
+[![flowbox](flow-box.png)](class.FlowBox.html)
+[![treeview](list-and-tree.png)](class.TreeView.html)
+[![iconview](icon-view.png)](class.IconView.html)
+[![overlay](overlay.png)](class.Overlay.html)
+[![stack](stack.png)](class.Stack.html)
+[![stackswitcher](stackswitcher.png)](class.StackSwitcher.html)
+[![stacksidebar](sidebar.png)](class.StackSidebar.html)
+[![popover](popover.png)](class.Popover.html)
+
+## Windows
+
+[![window](window.png)](class.Window.html)
+[![messagedialog](messagedialog.png)](class.MessageDialog.html)
+[![aboutdialog](aboutdialog.png)](class.AboutDialog.html)
+[![assistant](assistant.png)](class.Assistant.html)
+[![colorchooser](colorchooser.png)](class.ColorChooserDialog.html)
+[![filechooser](filechooser.png)](class.FileChooserDialog.html)
+[![fontchooser](fontchooser.png)](class.FontChooserDialog.html)
+[![appchooserdialog](appchooserdialog.png)](class.AppChooserDialog.html)
+[![pagesetupdialog](pagesetupdialog.png)](class.PageSetupUnixDialog.html)
+[![printdialog](printdialog.png)](class.PrintUnixDialog.html)
+[![shortcutswindow](shortcuts-window.png)](class.ShortcutsWindow.html)