Revert "docs: Added 3-month and 6-month subscription periods"

Per communication from Zeina, this doc is *not* supposed to go live until she gives the word that the feature is live--hopefully Sept. 30 but she's not sure.

This reverts commit 29b498bb.

Change-Id: I60ce8f60396aeee7b52dda5ded843897b722bce0