organization templates templates

[oliver-sanders]

GitHub lets us define issue templates at the organisation level, we can link through to our Discourse forum from this template too.

See for example:

https://github.com/jupyter-server/jupyter_server/issues/new/choose
https://github.com/jupyter-server/.github/blob/master/.github/ISSUE_TEMPLATE/config.yml

[hjoliver]

Nice, let's do it.