[This post was meant to be published in June 2015, but I forgot it until December...]
CPAN.io started with the once-a games, because it was an easy thing to do: thanks to CJM and NEILB existing boards, BOOK had a clear idea of what he wanted them to look like. And producing proper yearly boards was a nice stretch goal.
When NEILB started to work on his history of CPAN, it was immediately obvious (to BOOK) that it belonged to CPAN.io. Neil having started in a different repository, the first step was to copy the file over. Trouble started when people sent patches against the CPANio repository, instead of the cpan-history repository.
The solution to that is obviously DRY (Don't Repeat Yourself). If the authoritative source for the "history of CPAN" document is that other repository, let it be. Don't try to bring everything into the main CPANio repository.
On May 6 2015, KENTNL sent an email titled "Documenting best practices and the state of ToolChain guidelines using CPAN and POD" to the CPAN workers mailing-list. In his email, Kent explained how he wanted to document the best practices and policies of various Perl/CPAN projects and authors (as living documents, because practices and policies change over time, as we discover their limitations and figure out how to improve on them). In the course of the discussion, NEILB begged that these didn't end up on CPAN as documentation modules, since they would be artificially limited to the POD format as presented on http://search.cpan.org/ and http://metacpan.org/. Then BOOK offered to aggregate and host these documents on http://cpan.io/.
So the ref section of CPAN.io is now entirely made of documents that live in other repositories. CPAN.io is only following a specific branch, which enables the document authors to edit it according to their own policies and practices, while CPAN.io will always pick the latest version on the "published" branch.
As a first test, the history of CPAN document was removed and added as a reference, and all the patches that were applied against CPAN.io applied to the original repository and sent as pull request against it. They still need to be merged at the time of this writing.
Come play the CPAN game with us, fork cpan.io on github and send us patches and feature requests.