meta/new-web: use `--web` mode of `raco s3-sync`

A side effect of this change is that ".html" files bigger than
1k are gzipped, in addition to ".css" and ".js" files. I find
several web comments to the effect that gziping ".html" files works
fine, because all browsers support it, and no warnings against.
Since gzipping ".css" and ".js" files has worked fine for us, too,
lets take the plunge and try gzipping ".html".
web pages: update news to v6.1