[gthumb] README: rewritten in markdown format

[Paolo Bacchilega <paobac src gnome org>]

commit 0048d2bd697d335ff44197f533187d06880973dd
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Thu Nov 21 09:21:57 2019 +0100

    README: rewritten in markdown format

 README => README.md | 92 ++++++++++++++++++++++-------------------------------
 1 file changed, 38 insertions(+), 54 deletions(-)
---
diff --git a/README b/README.md
similarity index 65%
rename from README
rename to README.md
index 305e409f..69dee6c3 100644
--- a/README
+++ b/README.md
@@ -1,11 +1,9 @@
-This is the distribution of gThumb, an image viewer and browser utility
-for the GNOME environment.
+# gThumb
 
-Information about gthumb can be found at https://wiki.gnome.org/Apps/Gthumb.
+An image viewer and browser utility for the GNOME environment.
+More information can be found at https://wiki.gnome.org/Apps/Gthumb.
 
-
-What is gThumb
-==============
+## Features
 
  * gThumb is an image browser
 
@@ -54,67 +52,53 @@ What is gThumb
    + JPEG lossless transformations.
    + Find duplicated images.
 
+## Extensions
+
+  gThumb has a plug-in system for extensions. Some standard features
+  are implemented as extensions and are supplied with the standard
+  distribution. Users may write (and share) additional extensions.
 
-Licensing
-=========
+  See https://wiki.gnome.org/Apps/Gthumb/extensions for details.
+
+## Licensing
 
   This program is released under the terms of the GNU General Public
-  License (GNU GPL), either version 2 of the License, or (at your option) any 
+  License (GNU GPL), either version 2 of the License, or (at your option) any
   later version.
 
   You can find a copy of the license in the file COPYING.
 
+## Compiling
 
-Compiling
-=========
-
-  In order to build this program you need a working GNOME environment
-  version 2 or greater, with the development tools installed properly.
+  In order to build this program you need GNOME 3, with the development tools installed properly.
   The following is the detailed list of libraries you need:
 
-       * glib                  version >= 2.36.0
-       * gtk                   version >= 3.16
-       * gthread
-       * gmodule
-       * gio-unix
-
-  While not mandatory, these libraries greatly increase gThumb's
-  basic usefulness:
-
-       * exiv2                 version >= 0.21
-         (embedded metadata support)
-
-       * gstreamer             version >= 1.0.0
-         (video support)
+  * glib >= 2.38.0
+  * gtk  >= 3.16
+  * libpng
+  * zlib
+  * libjpeg
+  * gsettings-desktop-schemas
 
-       * libjpeg
-       * libtiff
-         (jpeg and tiff writing support)
+  While not mandatory, the following libraries greatly increase gThumb's basic usefulness:
 
+  * exiv2: embedded metadata support;
+  * gstreamer, gstreamer-plugins-base, gstreamer-video: audio/video support;
+  * libtiff: tiff writing support.
 
-  These libraries are optional:
-
-       * clutter               version >= 1.12.0
-       * clutter-gtk           version >= 1.0.0
-          (These libraries provide enhanced slideshow effects.)
-
-       * libraw
-          (This adds some support for RAW photos)
-
-
-
-Extensions
-==========
-
-  gThumb has a plug-in system for extensions. Some standard features
-  are implemented as extensions and are supplied with the standard
-  distribution. Users may write (and share) additional extensions.
-
-  See https://wiki.gnome.org/Apps/Gthumb/extensions for details.
+  Other optional libraries:
 
+  * libraw: some support for RAW photos;
+  * librsvg: display SVG images;
+  * libwebp: display and save WebP images;
+  * lcms2, colord: color profile support;
+  * champlain, champlain-gtk: view the place a photo was taken on a map;
+  * clutter, clutter-gtk: enhanced slideshow effects;
+  * libsoup, json-glib, webkit2gtk, libsecret: upload images to and download images from some web services 
such as facebook, flickr;
+  * brasero: write images and comments to CDs;
+  * bison, flex: web albums.
 
-Download
-========
+## Download
 
   * Tar archives can be found here:
 
@@ -129,5 +113,5 @@ Download
         ninja -C build
         sudo ninja -C build install
 
-    More development information is available at
-    https://wiki.gnome.org/Apps/Gthumb/development
+   More development information is available at
+   https://wiki.gnome.org/Apps/Gthumb/development