Add production guide to templates

[AndersAbel]

Our templates are meant to be usable/runnable out of the box, but there are still a few things that need to be fixed to be able to run in production. Some of these are detected runtime and result in warning logs (in memory store usage for example).

It would make sense to also add a comment block to the startup code with instructions and draft code for things that need to be added:

• Persistent grant store (only for templates running in memory)
• Data Protection
• ...

[leastprivilege]

or rather a link to a page that we control and can update