Fix old github url

... and remove the unmaintained description about version-release
mapping, because now it's described in [1].

[1] https://docs.openstack.org/puppet-openstack-guide/latest/install/releases.html

Change-Id: I19e24a8f6a1f34ce37f1c459e814b0a724479468

README.md

@@ -20,7 +20,6 @@ openstacklib
 7. [Contributors - Those with commits](#contributors)
 8. [Release Notes - Release notes for the project](#release-notes)
 9. [Repository - The project source code repository](#repository)
-10. [Versioning - Notes on the version numbering scheme](#versioning)
 
 Overview
 --------
@@ -306,7 +305,7 @@ Developer documentation for the entire puppet-openstack project.
 Contributors
 ------------
 
-* https://github.com/stackforge/puppet-openstacklib/graphs/contributors
+* https://github.com/openstack/puppet-openstacklib/graphs/contributors
 
 Release Notes
 -------------
@@ -317,19 +316,3 @@ Repository
 ----------
 
 * https://opendev.org/openstack/puppet-openstacklib
-
-Versioning
-----------
-
-This module has been given version 5 to track the puppet-openstack modules. The
-versioning for the puppet-openstack modules are as follows:
-
-```
-Puppet Module :: OpenStack Version :: OpenStack Codename
-2.0.0         -> 2013.1.0          -> Grizzly
-3.0.0         -> 2013.2.0          -> Havana
-4.0.0         -> 2014.1.0          -> Icehouse
-5.0.0         -> 2014.2.0          -> Juno
-6.0.0         -> 2015.1.0          -> Kilo
-7.0.0         -> 2015.2.0          -> Liberty
-```