[www-ko_KR] Publish install-guide (Mitaka&Liberty)
[www-ko_KR] Publish install-guide (Mitaka&Liberty)

Korean i18n team 100% translated both install-guide and
common(-rst) for Mitaka and Liberty releases.

This commit adds the links to install-guides for
Mitaka and Liberty releases on Korean docs main page.

Change-Id: I9c339f6c89e8544bcedb30ddb6651c0ad8dc9209

openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals