Documentation: agree on principles of writing examples

[grzesuav]

As pointed out in https://github.com/AmitKumarDas/metac/pull/122#discussion_r403272269

I think that having common agreement on principles of writing examples would make it easier to use.

Some initial though from my side :

• separate section with setting up local kubernetes - can be divided to sections of refference to upstream distributions (as probably they have it explained better) + eventually small additions (how to build docker images and use them in given solution)
• use plain kubectl without reference to underlying platform unless necessary. Can point to general section - like (Before start - prepare environment of your choice as descried in [hyperlink to our docs])

[AmitKumarDas]

This will be a good idea to follow. Probably a template for examples will be a good starting point. kind, k3s, minikube etc can be placed as separate scripts if required or referred to their home pages.

[AmitKumarDas]

Additional Notes: KIND along with local docker registry helps one to test sample controllers without the need to push images to image registry before testing the same. If there are alternatives then those may be documented &/ scripted in the examples/ folder itself. Specific example controllers can then make use of any of the documented ways to test the same.