Perl Toolchain documents

The dates following the document title are creation date and latest modification date.

• The Oslo Consensus [2013-03-16]
• The Lancaster Consensus [2013-04-17 – 2015-05-10]
• The Berlin Consensus [2015-04-20 – 2015-05-11]
• The Lyon Compromise from the Perl QA Conference [2016-02-27 – 2016-04-23]