Document and conform to conventions for naming URLs

[garrison]

I only vaguely recall the rules we followed when choosing what to name pages within the wiki portion of the site, i.e., pages outside the group and user namespaces. The best I can remember is that we chose to place something, e.g., in the "English wiki" (content/en/) if the document's title/location was written in English. This is independent of whether a lesson actually teaches English, which is instead coded by the target-languages taxonomy.

A few questions:

• Am I indeed remembering this correctly?
• Does the existing convention make the most sense going forward?
• How, in particular, do we want to handle the user and group sections from the old site?
• If I am having trouble remembering the guidelines on this, I doubt it was followed by all contributors to the site, so there is surely cleanup to do.
• Can our ideal scheme be made to work with Hugo's multilingual feature?

When content is moved or consolidated, an alias should be left at any old location(s). Since we first started the wiki, we have consistently followed the principle that cool URIs don't change.

• Decide and document conventions
• Implement site-wide conformance