SotD sections for fxtf and houdini drafts

[ To the member list since it's administrivia, but cc:ed to a public
  list since it may as well be public. ]

Current CSSWG drafts have boilerplate in the "Status of this
document" section that says:

> GitHub Issues are preferred for discussion of this specification.
> When filing an issue, please put the text “css-animations” in the
> title, preferably like this: “[css-animations] …summary of
> comment…”. All issues and comments are archived, and there is also
> a historical archive. 

However, fxtf drafts and houdini drafts still have the old text:

> The (archived) public mailing list public-fx@w3.org (see
> instructions) is preferred for discussion of this specification.
> When sending e-mail, please put the text “motion” in the subject,
> preferably like this: “[motion] …summary of comment…” 
or:
> The (archived) public mailing list public-houdini@w3.org (see
> instructions) is preferred for discussion of this specification.
> When sending e-mail, please put the text “css-paint-api” in the
> subject, preferably like this: “[css-paint-api] …summary of
> comment…” 

I *think* we should fix these to be similar to the CSSWG ones,
although I'm not 100% sure.  Is that the case?

That said, fixing the fxtf boilerplate requires fixing the issue in:
https://lists.w3.org/Archives/Member/w3c-css-wg/2016OctDec/0090.html
about lack of an archive list for fxtf-draft issues.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)