Document the module config required fields

[stefanprodan]

Changes:

• Explain which #Config fields are used by Timoni to inject the name, namespace, module version and cluster version.
• Explain which changes are acceptable for Timoni's entry point.
• Move the Kubernetes min version constraint to #Config.

Ref: #251

[jmgilman]

Just two minor nits, otherwise LGTM.

[jmgilman]

Just a note on this:

if instance.config.test.enabled {
	apply: test: [ for obj in instance.tests {obj}]
}

Even though this is a conditional, the module author doesn't really get a chance to "optionally" write tests. The reason being:

1. The conditional references config.test which makes it a required field
2. If you leave config.test and just don't implement tests, the consumer of the package is left wondering what this test option does (and would probably be disappointed it does nothing).

So the options are you either implement tests or unwire all of the logic around tests (which IIRC was in a few more places). This is a very minor nitpick, so it's probably fine as is, but this was just my experience coming into it (perhaps we'll adopt the testing with jobs strategy, but it's not something we've historically practiced in this way).

[stefanprodan]

Oh yeah that's the issue with the current blueprint, which turned out it's not quite minimal. Will work on that next, planning to have more flavours for the init command and also allow custom blueprints.