[devhelp] docs: Restructure the README

[Emmanuele Bassi <ebassi src gnome org>]

commit 083bc08ae337007e86717e95c20f23787c0a99df
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri Jul 9 17:05:56 2021 +0100

    docs: Restructure the README
    
    Move the description up top, and fix the link to the contribution
    guidelines.

 README.md | 42 +++++++++++++++++++-----------------------
 1 file changed, 19 insertions(+), 23 deletions(-)
---
diff --git a/README.md b/README.md
index 2d83a3c2..c3c3595b 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,24 @@
 Devhelp
 =======
 
-The Devhelp web page:
+Description
+-----------
+
+Devhelp is a developer tool for browsing and searching API documentation.
+It provides an easy way to navigate through libraries and to search by
+function, struct, or macro.
+
+The documentation must be installed locally, so an internet connection is
+not needed to use Devhelp.
 
-https://wiki.gnome.org/Apps/Devhelp
+Devhelp works natively with the documentation generators used by the GNOME
+project libraries. Other development platforms can be supported as well, as
+long as the API documentation is available in HTML and a `*.devhelp2` index
+file is generated.
+
+Devhelp integrates with other applications such as Glade, Builder or
+Anjuta, and plugins are available for different text editors (gedit, Vim,
+Emacs, Geany, …).
 
 Installation of the Devhelp Flatpak
 -----------------------------------
@@ -13,7 +28,7 @@ Installation of the Devhelp Flatpak
 How to contribute
 -----------------
 
-See the [HACKING](HACKING) file.
+See the [contribution guide](CONTRIBUTING.md).
 
 Dependencies
 ------------
@@ -23,25 +38,6 @@ Dependencies
 - WebKitGTK
 - gsettings-desktop-schemas
 
-Description
------------
-
-Devhelp is a developer tool for browsing and searching API documentation.
-It provides an easy way to navigate through libraries and to search by
-function, struct, or macro.
-
-The documentation must be installed locally, so an internet connection is
-not needed to use Devhelp.
-
-Devhelp works natively with GTK-Doc, so the GTK and GNOME libraries are
-well supported. But other development platforms can be supported as well,
-as long as the API documentation is available in HTML and a `*.devhelp2`
-index file is generated.
-
-Devhelp integrates with other applications such as Glade, Builder or
-Anjuta, and plugins are available for different text editors (gedit, Vim,
-Emacs, Geany, …).
-
 Integration with other developer tools
 --------------------------------------
 
@@ -54,7 +50,7 @@ Devhelp also provides a shared library, to integrate the GTK widgets inside an
 IDE. It is used for example by Builder and Anjuta.
 
 For the `--search` command line option, see the class description of
-DhKeywordModel, the search string supports additional features useful for IDEs
+`DhKeywordModel`, the search string supports additional features useful for IDEs
 or other developer tools.
 
 Other documentation