[retro-gtk] doc: Describe the library in the Overview chapter

[Adrien Plazas <aplazas src gnome org>]

commit 8183991aac08fa703913832296a63b2b8e569a72
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Sun Nov 15 15:55:23 2020 +0100

    doc: Describe the library in the Overview chapter
    
    This also drops the wrongly placed short decriptions.

 doc/retro-gtk-doc.xml | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)
---
diff --git a/doc/retro-gtk-doc.xml b/doc/retro-gtk-doc.xml
index 41ee06e6..6fb89811 100644
--- a/doc/retro-gtk-doc.xml
+++ b/doc/retro-gtk-doc.xml
@@ -15,11 +15,6 @@
         The latest version can be found online at
         <ulink role="online-location" 
url="https://gnome.pages.gitlab.gnome.org/retro-gtk/";>https://gnome.pages.gitlab.gnome.org/retro-gtk/</ulink>.
       </para>
-      <para>
-        <ulink type="http" url="&package_url;">&package_name;</ulink> is a
-        <ulink type="http" url="https://www.libretro.com/";>Libretro</ulink>
-        frontend as a library.
-      </para>
       <para>
         If you find any issues in this API reference, please report it using
         <ulink type="http" url="&package_bugreport;">the bugtracker</ulink>.
@@ -35,6 +30,30 @@
   <chapter id="overview">
     <title>&package_name; Overview</title>
 
+    <para>
+      &package_name;, the GTK Libretro frontend framework.
+    </para>
+
+    <para>
+      <ulink type="http" url="https://www.libretro.com/";>Libretro</ulink> is a
+      plugin format design to implement video game console emulators, video
+      games and similar multimedia software.
+      Such plugins are called Libretro cores.
+    </para>
+
+    <para>
+      &package_name; is a framework easing the use of Libretro cores in
+      conjunction with
+      <ulink type="http" url="https://www.gtk.org/";>GTK</ulink>.
+    </para>
+
+    <para>
+      It encourages the cores to be installed in a well defined centralized
+      place — namely the <filename>libretro</filename> subdirectory of your
+      <filename>lib</filename> directory — and it recommends them to come with
+      Libretro core descriptors.
+    </para>
+
     <xi:include href="libretro-core-descriptor.xml"/>
     <xi:include href="reference-test-case.xml"/>
   </chapter>