Fix some wrong strings in ko_KR docs index page
Fix some wrong strings in ko_KR docs index page

1. '오신것을' must have a space between '오신' and '것을'
2. <sting> -> '<strong>'
3. A meaningless grave accent exists
4. elaborate an ambiguous expression more concisely
5. remove a period which is not used in the base document
6. '관심있으신가요' has to have a space between '관심' and '있으신가요'

As index page is like a face of this project, any trivial spelling error
cannot be allowed.

Change-Id: Ie769e23bce348ddbe7c233a59c82fe7c51748057

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