Migrate Lucene's Moin wiki to Confluence

We have a deadline end of June to migrate Moin wiki to Confluence.

This Jira will track migration of Lucene's https://wiki.apache.org/lucene-java/ over to https://cwiki.apache.org/confluence/display/LUCENE

The old Confluence space will be overwritten as it is not used.

After migration we'll clean up and weed out what is not needed, and then start moving developer-centric content into the main git repo (which will be covered in other JIRAs)