Open coach registration form

[vsmart]

• copy old coach registration form
• update coach form to include question for child care https://github.com/clojurebridge-berlin/organization/issues/138
• set up "save responses in google spreadsheet"
• setup coach form auto response -- email template is here https://github.com/clojurebridge-berlin/organization/wiki/%5Bemail%5D-Coach-Signup-Confirmation-Email
• test that sign up and response is working properly
• set form to public
• link new form in https://github.com/clojurebridge-berlin/clojurebridge-berlin.github.io/pull/54

Assigning to @lislis who said she could pick this one up!

[lislis]

• copied form
• added/ removed fields according to #138
• setup auto response
• collect answers in spreadsheet
• set form to accept responses

[lislis]

Closing this, all we need to do is merge the PR