README: update content and format

* Change to markdown format
* Include an introduction
* Remove the commit mailing list from the contacts
* Add the IRC channel to the contacts
* Move 'S/Key' section to doc/README.skey
* Move authors and maintainers to AUTHORS.md

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

AUTHORS.md

@@ -1,42 +1,14 @@
-Shadow SITES
-============
-
-Homepage
-	https://github.com/shadow-maint/shadow
-
-Issue tracker
-	https://github.com/shadow-maint/shadow/issues
-
-Releases
-	https://github.com/shadow-maint/shadow/releases
-
-Mailing lists
-	for general discuss: pkg-shadow-devel@alioth-lists.debian.net
-	commit list: pkg-shadow-commits@alioth-lists.debian.net
-
-Mailing lists subscription
-	https://alioth-lists.debian.net/mailman/listinfo/pkg-shadow-devel
-	https://alioth-lists.debian.net/mailman/listinfo/pkg-shadow-commits
-
-Mailing lists archives:
-	https://alioth-lists.debian.net/pipermail/pkg-shadow-devel/
-	https://alioth-lists.debian.net/pipermail/pkg-shadow-commits/
-
-S/Key support:
-	Shadow can be built with S/Key support using the S/Key package from:
-
-	http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libskey/
-	or
-	https://gentoo.osuosl.org/distfiles/skey-1.1.5.tar.bz2
-
-Authors and contributors
-========================
-
 Thanks to at least the following people for sending patches, bug
-reports and various comments.  This list may be incomplete, I received
+reports and various comments. This list may be incomplete, I received
 a lot of mail...
 
+# Maintainers
+Tomasz Kłoczko <kloczek@pld.org.pl> (2000-2007)
+Nicolas François <nicolas.francois@centraliens.net> (2007-2014)
+Serge E. Hallyn <serge@hallyn.com> (2014-now)
+Christian Brauner <christian@brauner.io> (2019-now)
 
+# Authors and contributors
 Adam Rudnicki <adam@v-lo.krakow.pl>
 Alan Curry <pacman@tardis.mars.net>
 Aleksa Sarai <cyphar@cyphar.com>
@@ -114,12 +86,3 @@ Tim Hockin <thockin@eagle.ais.net>
 Timo Karjalainen <timok@iki.fi>
 Ulisses Alonso Camaro <ulisses@pusa.eleinf.uv.es>
 Werner Fink <werner@suse.de>
-
-Maintainers
-===========
-
-Tomasz Kłoczko <kloczek@pld.org.pl> (2000-2007)
-Nicolas François <nicolas.francois@centraliens.net> (2007-2014)
-Serge E. Hallyn <serge@hallyn.com> (2014-now)
-Christian Brauner <christian@brauner.io> (2019-now)
-

README.md

@@ -0,0 +1,36 @@
+# shadow-utils
+
+## Introduction
+The shadow-utils package includes the necessary programs for
+converting UNIX password files to the shadow password format, plus
+programs for managing user and group accounts. The pwconv command
+converts passwords to the shadow password format. The pwunconv command
+unconverts shadow passwords and generates a passwd file (a standard
+UNIX password file). The pwck command checks the integrity of password
+and shadow files. The lastlog command prints out the last login times
+for all users. The useradd, userdel, and usermod commands are used for
+managing user accounts. The groupadd, groupdel, and groupmod commands
+are used for managing group accounts.
+
+## Sites
+* [Homepage](https://github.com/shadow-maint/shadow)
+* [Issue tracker](https://github.com/shadow-maint/shadow/issues)
+* [Releases](https://github.com/shadow-maint/shadow/releases)
+
+## Contacts
+There are several ways to contact us:
+* [the general discussion mailing list](
+  https://alioth-lists.debian.net/mailman/listinfo/pkg-shadow-devel)
+* the #shadow IRC channel on libera.chat:
+  * irc://irc.libera.chat/shadow
+
+### Mailing archives
+* [the general discussion mailing list archive](
+  https://alioth-lists.debian.net/pipermail/pkg-shadow-devel/)
+* [the commit mailing list archive](
+  https://alioth-lists-archive.debian.net/pipermail/pkg-shadow-commits/),
+  only used for historical purposes
+
+## Authors and maintainers
+Authors and maintainers are listed in [AUTHORS.md](
+https://github.com/shadow-maint/shadow/blob/master/AUTHORS.md).

doc/README.skey

@@ -0,0 +1,4 @@
+# S/Key support
+shadow-utils can be built with S/Key support using the S/Key package from:
+* http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libskey/ or
+* https://gentoo.osuosl.org/distfiles/skey-1.1.5.tar.bz2