Decide on a method to archive content that is no longer current

[tobie]

In #1336, @mhdawson expressed concern around losing historical context and intent when archiving content that is no longer relevant to the CPC's day to day. This concern was echoed by others in the following CPC call.

I suggest we define a good strategy to archive such content and document it so it is easier to keep the CPC's repo lean.

Here are a few options to get us started.

1. An archive index page linking to permalinks of archived content
2. An archive directory with just a README explaining what it is
3. An archive directory with an archive index

[tobie]

This was discussed in the August 13 working session.

After a lot of back and forth we ended up agreeing that we should be focusing on making it as easy as possible to keep the repository current and up to date.

We agreed to default to removing content and not indexing it, in favor of writing good commit messages that would easily surface content in case someone was searching for it.

Additionally, we agreed to allow content to be added back in, if people thought it was relevant to do so.

[tobie]

The conclusions and recommendations of the working session were shared with the CPC in today's CPC call. It was met with approval from the CPC which thought that the rationale was sound and decided to go ahead with it.