Task: add links to signage app

[ijdickinson]

There should be a link to the app from:

• the environment.data.gov.uk landing page

• the bathing water profiles explorer

[ijdickinson]

@tamsinappleton I've put a link from the bathing water profiles page to the signage generator, on staging. E.g: http://ea-rbwd-staging.epimorphics.net/bwq/profiles/profile.html?_search=cle&site=ukk1202-36000

I expect you'll want to tweak the wording, but it's enough to be able to show Defra how it works. I can't easily show a test version of the link from environment.data.gov.uk, since we don't have a staging page for that site. But it's easy, I hope, to imagine how it would work. Parenthetically, it would be helpful if you & Jonathan could suggest the wording you'd like for that link.

[tamsinappleton]

@ijdickinson Link on profiles page is fine

[ijdickinson]

env.dgu entry added for testing, see #107

[tamsinappleton]

Separate ticket for EA datasets (which looks fine, I've closed). Link from profiles page fine.