Convert README to asciidoc format

README.md → README.asciidoc

-## Description
+= gitchart
+:author: Sébastien Helleu
+:email: flashcode@flashtux.org
+:lang: en
+
+== Description
 `gitchart.py` is a Python script to build charts from a Git repository.
@@ -10,41 +15,53 @@ It can build following charts, as SVG or PNG:
 * commits by hour of week (dot chart)
 * files by type (pie chart)
-## Install
+== Install
 The script requires Python >= 2.7 and [Pygal](http://pygal.org/), which can be
 installed with this command:
-    # pip install pygal
-Note: cairosvg is required to generate PNG files.
-## Usage
+----
+# pip install pygal
+----
+[NOTE]
+`cairosvg` is required to generate PNG files.
+== Usage
 See output of command:
-    $ python gitchart.py -h
-## Examples
+----
+$ python gitchart.py -h
+----
+== Examples
 Generate pie chart with authors:
-    $ python gitchart.py -t "Git authors on project X" -r /path/to/gitrepo/ authors authors.svg
+----
+$ python gitchart.py -t "Git authors on project X" -r /path/to/gitrepo/ authors authors.svg
+----
 Generate bar chart with commits by year:
-    $ python gitchart.py -r /path/to/gitrepo/ commits_year commits_year.svg
+----
+$ python gitchart.py -r /path/to/gitrepo/ commits_year commits_year.svg
+----
 Generate bar chart with commits by version (tag):
-    $ cd /path/to/gitrepo/
-    $ git tag | python /path/to/gitchart.py commits_version /tmp/commits_version.svg
-## Demo
-`gitchart.py` is used to build statistics for WeeChat: http://weechat.org/dev/stats/
-## Copyright
+----
+$ cd /path/to/gitrepo/
+$ git tag | python /path/to/gitchart.py commits_version /tmp/commits_version.svg
+----
+== Demo
+`gitchart.py` is used to build statistics for WeeChat:
+https://weechat.org/dev/stats/
+== Copyright
 Copyright (C) 2013-2016 Sébastien Helleu <flashcode@flashtux.org>