cleanup of site and its maintenance/documentation

[jzacsh]

trafficstars

builds atop #1099 to try to cleanup our site's generation so updating is a bit easier to understand without making mistakes (like, eg, deleting the site).

[CLAassistant]

All committers have signed the CLA.

[jzacsh]

@lisad feel free to replicate the cleanup-sentiment of course if you want, but I'm closing this since it's old now. (I think the problems are still true: worth just documenting how to the site's built, and deleting ephemeral files)