Added section about cookies allowed by Varnish

[holtkamp]

The current documentation suggests that NO requests with cookies are allowed by Varnish, which is not the case.

[pst]

Hi Menno,

apologies for the late reply. While we really appreciate your initiative and effort, we're not quite ready to make this information part of the official documentation. Some of the features are still to be considered experimental and there are some pending issues we need to resolve before we feel comfortable to make it available to more people or worst case, we can't and need to drop some of the features again.

For the time being I'll leave this PR open and we'll update it with new information when available.

Thanks again
Philipp

[holtkamp]

ok, no problemo