roles/archwiki: Initial commit with defaults

Create a default file for archwiki.

roles/archwiki/defaults/main.yml

+---
+archwiki_dir: '/srv/http/archwiki'
+archwiki_domain: 'wiki.archlinux.org'
+archwiki_user: 'archwiki'
+
+archwiki_db: 'archwiki'
+archwiki_db_host: 'localhost'
+archwiki_db_user: 'archwiki'