Add FAQ on "which api version should I use"

[howardjohn]

See https://blog.howardjohn.info/posts/crd-versioning/

tl;dr: it usually doesn't matter as much as people think. Always use the latest if you are a user; use the oldest version you need to support for integration authors

[priyanshsao]

hey @howardjohn , i would like to work on this issue , since i am new to open source , can you provide me some guidance for solving this issue.

[kfaseela]

@priyanshsao : There is already a PR up for review for this from @Darshan174

[craigbox]

@priyanshsao Please see #15329 (comment).

I don't actually think this is a good first issue, because you need to understand (a) something pretty complex about Kubernetes (b) how Istio implements it (c) how to explain it trivially to a new user.

I should be able to do all 3, but I suspect it will take me an hour or so of thought to get something that is well crafted.