[amtk] readme: Markdown format, plus small update

[Sébastien Wilmet <swilmet src gnome org>]

commit 33ec171156ebc49d6dad568e6ba39470edb272e1
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Nov 6 09:10:45 2020 +0100

    readme: Markdown format, plus small update

 README => README.md | 29 +++++++++--------------------
 1 file changed, 9 insertions(+), 20 deletions(-)
---
diff --git a/README b/README.md
similarity index 52%
rename from README
rename to README.md
index c08c72a..6b52707 100644
--- a/README
+++ b/README.md
@@ -8,11 +8,9 @@ GtkUIManager replacement based on GAction. It is suitable for both a
 traditional UI or a modern UI with a GtkHeaderBar.
 
 The Amtk library is free software and is released under the terms of the GNU
-Lesser General Public License, see the 'COPYING' file for more information.
+Lesser General Public License, see the `COPYING` file for more information.
 
-The Amtk web page:
-
-    https://wiki.gnome.org/Projects/Amtk
+See also the [Amtk web page](https://wiki.gnome.org/Projects/Amtk).
 
 Dependencies
 ------------
@@ -23,25 +21,16 @@ Dependencies
 Installation
 ------------
 
-Simple install procedure from a tarball:
-
-  $ ./configure
-  $ make
-  [ Become root if necessary ]
-  $ make install
-
-See the file 'INSTALL' for more detailed information.
-
-From the Git repository, the 'configure' script and the 'INSTALL' file are not
-yet generated, so you need to run 'autogen.sh' instead, which takes the same
-arguments as 'configure'.
+To build the latest version of Amtk plus its dependencies from Git,
+[Jhbuild](https://wiki.gnome.org/Projects/Jhbuild) is recommended.
 
-To build the latest version of Amtk plus its dependencies from Git, Jhbuild is
-recommended:
+Documentation
+-------------
 
-    https://wiki.gnome.org/Projects/Jhbuild
+See the `gtk_doc` Meson option. A convenient way to read the API documentation
+is with the [Devhelp](https://wiki.gnome.org/Apps/Devhelp) application.
 
 How to contribute
 -----------------
 
-See the file 'HACKING'.
+See the file `HACKING`.