Allow to create templates, that'd appear upon opening new tickets in Github using Tablero.

[kchnr]

This is a feature that we're looking after, since we are using a more manual version of it in our project https://github.com/servicosgovbr. Github doesn't support it, so we think that it would be a great addition to Tablero.

Our user case:

We have a number o things that we need to check in our project (depending on the repository) before moving an issue to "Done", regardless of the specifics of a feature. So, for instance, we'd have a checklist of items in a section that we'd check before sending it to done, and any details that we'd add when creating a new issue.

So we'd press something like "New Issue", and this template would appear in edit mode.

What do you people think? This is already a real client need.

@oliviagj This is the ticket that I asked you about, if you want to add more to it.