suggestion to rephrase https://www.debian.org/releases: make clear the names 'stretch' and 'sid' are invariant

Dear Debian WWW team:

May I suggest to rephrase
   »The current "_testing_" distribution is _stretch_«
as
   »The "_testing_" distribution is always called _stretch_«,
and
   similarly for _unstable_ / _sid_.

Rationale:

The word "current" is confusing, especially in the context
set by the preceding paragraph about the codename of "stable".
For many years, I thought "stretch" was to become the code
name of the next "stable" release, "sid" would then be promoted
from "unstable" to "testing", and a new codename would be chosen
for the next "unstable".

(I even persisted in this error when these name changes
did not happen upon release of "squeeze", "wheezy", "jessie" -
I just thought my memory was unable to keep those idiotic
codenames apart)

Thanks you for considering this - Joachim