description for welcome pages

[nazlimoghaddam]

Adding description for welcome pages

:ballot_box_with_check: Definition of Done checklist

• [x] Meaningful title and valuable description in pull request
• [x] Code change tested manually if not covered by automated tests
• [x] Pull request linked to one or more issues/stories
• [x] Acceptance criteria of the linked stories satisfied
• [x] Code change comprehended by those who approved it
• [x] State of target branch maintained or improved after the code change