[tepl] Improve intro

[Sébastien Wilmet <swilmet src gnome org>]

commit 227379aff4af8479ae17dd7e3e649402ace52ad4
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Mon Jun 12 06:27:27 2017 +0200

    Improve intro

 README                      |   12 +++---------
 docs/reference/intro.xml.in |   30 +++++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 12 deletions(-)
---
diff --git a/README b/README
index bc09152..7c88caa 100644
--- a/README
+++ b/README
@@ -1,14 +1,14 @@
 Tepl - Text editor product line
 ===============================
 
-This is version 2.0.1 of Tepl.
+This is version 2.99.0 of Tepl.
 
 Tepl is a library that eases the development of GtkSourceView-based text
 editors and IDEs.
 
 Tepl was previously known as Gtef (GTK+ text editor framework). The project has
-been renamed to have a more beautiful name. The end of Tepl is pronounced like
-apple.
+been renamed in June 2017 to have a more beautiful name. The end of Tepl is
+pronounced like “apple”.
 
 The Tepl website:
 
@@ -19,12 +19,6 @@ Some background on why this project has been created:
     https://wiki.gnome.org/Apps/Gedit/ReusableCode
     https://wiki.gnome.org/Projects/GtkSourceView/TdiFramework
 
-The final goal is to create a Tabbed Document Interface (TDI) framework
-suitable for text editors.
-
-But the first short-term goal is to have a higher-level API to load and save a
-file. All the errors would be handled by Tepl, showing GtkInfoBars etc.
-
 Maybe some of the Tepl features will be moved to GtkSourceView when it's
 considered more stable. So Tepl can also be seen as an incubator for some
 GtkSourceView features.
diff --git a/docs/reference/intro.xml.in b/docs/reference/intro.xml.in
index 185d8b6..8fb161c 100644
--- a/docs/reference/intro.xml.in
+++ b/docs/reference/intro.xml.in
@@ -11,12 +11,36 @@
   <title>Introduction</title>
 
   <para>
-    Tepl is a library that eases the development of GtkSourceView-based text
-    editors and IDEs. Tepl is the acronym for “Text editor product line”.
+    Tepl is a library that eases the development of
+    <ulink url="https://wiki.gnome.org/Projects/GtkSourceView";>GtkSourceView</ulink>-based
+    text editors and IDEs. Tepl is the acronym for “Text editor product line”.
   </para>
 
   <para>
-    See the <ulink url="https://wiki.gnome.org/Projects/Tepl";>Tepl website</ulink>.
+    Tepl was previously known as Gtef (GTK+ text editor framework). The project
+    has been renamed in June 2017 to have a more beautiful name. The end of Tepl
+    is pronounced like “apple”.
+  </para>
+
+  <para>
+    The Tepl library follows a product line approach (see the book
+    <ulink 
url="https://www.amazon.com/Feature-Oriented-Software-Product-Lines-Implementation/dp/3642375200/";>Feature-Oriented
+    Software Product Lines: Concepts and Implementation</ulink>).
+    Instead of creating one general-purpose text editor or IDE with a plugin
+    system, the idea is to create several <emphasis>specialized</emphasis> text
+    editors. For example specialized for one programming language, or one
+    development platform, or a small group of related languages. By being
+    specialized, an application is potentially better at what it does. It
+    follows more closely the UNIX philosophy to do only one thing but doing it
+    well. And it better follows the GNOME philosophy: writing applications that
+    Just Works; when a user opens the text editor for the first time, it should
+    work out-of-the-box, without the need to find, install and configure
+    plugins. Of course it still makes sense to develop one general-purpose text
+    editor for the languages not yet covered by specialized text editors.
+  </para>
+
+  <para>
+    See also the <ulink url="https://wiki.gnome.org/Projects/Tepl";>Tepl web page</ulink>.
   </para>
 
   <para>