docs: Split dependencies from related libraries

We currently list everything as a dependencies, regardless of whether
it actually is; this is a source of confusion for users that read the
GTK documentation.

Gi-docgen has a new "related" key in the project configuration which
allows us to list libraries that are merely related to the namespace
we are documenting; the "dependencies" key is used to document the
actual namespace dependencies, now.

docs/reference/gdk/gdk4-wayland.toml.in

@@ -7,13 +7,14 @@ authors = "GTK Development Team"
 logo_url = "gtk-logo.svg"
 license = "GPL-2.1-or-later"
 description = "The GTK toolkit"
-dependencies = [ "GObject-2.0" ]
 devhelp = true
 
-  [dependencies."GObject-2.0"]
-  name = "GObject"
-  description = "The base type system library"
-  docs_url = "https://docs.gtk.org/gobject/"
+dependencies = ["Gdk-4.0"]
+
+  [dependencies."Gdk-4.0"]
+  name = "GDK"
+  description = "The GTK drawing kit"
+  docs_url = "https://docs.gtk.org/gdk/"
 
 [theme]
 name = "basic"

docs/reference/gdk/gdk4-x11.toml.in

@@ -7,13 +7,13 @@ authors = "GTK Development Team"
 logo_url = "gtk-logo.svg"
 license = "GPL-2.1-or-later"
 description = "The GTK toolkit"
-dependencies = [ "GObject-2.0" ]
+dependencies = ["Gdk-4.0"]
 devhelp = true
 
-  [dependencies."GObject-2.0"]
-  name = "GObject"
-  description = "The base type system library"
-  docs_url = "https://docs.gtk.org/gobject/"
+  [dependencies."Gdk-4.0"]
+  name = "GDK"
+  description = "The GTK drawing kit"
+  docs_url = "https://docs.gtk.org/gdk4/"
 
 [theme]
 name = "basic"

docs/reference/gdk/gdk4.toml.in

@@ -8,7 +8,7 @@ authors = "GTK Development Team"
 logo_url = "gtk-logo.svg"
 license = "LGPL-2.1-or-later"
 description = "The GTK toolkit"
-dependencies = [ "GObject-2.0", "cairo-1.0", "Pango-1.0", "GdkWayland-4.0",  "GdkX11-4.0" ]
+dependencies = ["GObject-2.0", "Gio-2.0", "cairo-1.0", "Pango-1.0", "GdkPixbuf-2.0"]
 devhelp = true
 search_index = true
 
@@ -17,6 +17,11 @@ search_index = true
   description = "The base type system library"
   docs_url = "https://docs.gtk.org/gobject/"
 
+  [dependencies."Gio-2.0"]
+  name = "GIO"
+  description = "GObject Interfaces and Objects, Networking, IPC, and I/O"
+  docs_url = "https://docs.gtk.org/gio/"
+
   [dependencies."cairo-1.0"]
   name = "Cairo"
   description = "A 2D graphics library with support for multiple output devices"
@@ -27,12 +32,19 @@ search_index = true
   description = "Text shaping and rendering"
   docs_url = "https://docs.gtk.org/Pango/"
 
-  [dependencies."GdkWayland-4.0"]
+  [dependencies."GdkPixbuf-2.0"]
+  name = "GdkPixbuf"
+  description = "Image data loading"
+  docs_url = "https://docs.gtk.org/gdk-pixbuf/"
+
+related = ["GdkWayland-4.0", "GdkX11-4.0"]
+
+  [related."GdkWayland-4.0"]
   name = "GdkWayland"
   description = "GDK Wayland Backend"
   docs_url = "https://docs.gtk.org/gdk4-wayland/"
 
-  [dependencies."GdkX11-4.0"]
+  [related."GdkX11-4.0"]
   name = "GdkX11"
   description = "GDK X11 Backend"
   docs_url = "https://docs.gtk.org/gdk4-x11/"

docs/reference/gsk/gsk4.toml.in

@@ -8,25 +8,16 @@ authors = "GTK Development Team"
 logo_url = "gtk-logo.svg"
 license = "LGPL-2.1-or-later"
 description = "The GTK toolkit"
-dependencies = [ "GObject-2.0", "Graphene-1.0", "Pango-1.0", "Gdk-4.0" ]
 devhelp = true
 search_index = true
 
-  [dependencies."GObject-2.0"]
-  name = "GObject"
-  description = "The base type system library"
-  docs_url = "https://docs.gtk.org/gobject/"
+dependencies = ["Graphene-1.0", "Gdk-4.0"]
 
   [dependencies."Graphene-1.0"]
   name = "Graphene"
   description = "A thin layer of mathematical types for 3D libraries"
   docs_url = "https://ebassi.github.io/graphene/docs/"
 
-  [dependencies."Pango-1.0"]
-  name = "Pango"
-  description = "Text shaping and rendering"
-  docs_url = "https://docs.gtk.org/Pango/"
-
   [dependencies."Gdk-4.0"]
   name = "GDK"
   description = "The GTK windowing system abstraction"

docs/reference/gtk/gtk4.toml.in

@@ -8,24 +8,10 @@ authors = "GTK Development Team"
 logo_url = "gtk-logo.svg"
 license = "LGPL-2.1-or-later"
 description = "The GTK toolkit"
-dependencies = [ "GObject-2.0", "Graphene-1.0", "Pango-1.0", "Gdk-4.0", "Gsk-4.0" ]
 devhelp = true
 search_index = true
 
-  [dependencies."GObject-2.0"]
-  name = "GObject"
-  description = "The base type system library"
-  docs_url = "https://docs.gtk.org/gobject/"
-
-  [dependencies."Graphene-1.0"]
-  name = "Graphene"
-  description = "A thin layer of mathematical types for 3D libraries"
-  docs_url = "https://ebassi.github.io/graphene/docs"
-
-  [dependencies."Pango-1.0"]
-  name = "Pango"
-  description = "Text shaping and rendering"
-  docs_url = "https://docs.gtk.org/Pango/"
+dependencies = ["Gdk-4.0", "Gsk-4.0"]
 
   [dependencies."Gdk-4.0"]
   name = "GDK"
@@ -37,6 +23,28 @@ search_index = true
   description = "The GTK rendering abstraction"
   docs_url = "https://docs.gtk.org/gsk4/"
 
+related = ["Pango-1.0", "Graphene-1.0", "GObject-2.0", "Gio-2.0"]
+
+  [related."GObject-2.0"]
+  name = "GObject"
+  description = "The base type system library"
+  docs_url = "https://docs.gtk.org/gobject/"
+
+  [related."Gio-2.0"]
+  name = "GIO"
+  description = "GObject Interfaces and Objects, Networking, IPC, and I/O"
+  docs_url = "https://docs.gtk.org/gio/"
+
+  [related."Graphene-1.0"]
+  name = "Graphene"
+  description = "A thin layer of mathematical types for 3D libraries"
+  docs_url = "https://ebassi.github.io/graphene/docs"
+
+  [related."Pango-1.0"]
+  name = "Pango"
+  description = "Text shaping and rendering"
+  docs_url = "https://docs.gtk.org/Pango/"
+
 [theme]
 name = "basic"
 show_index_summary = true