Documentation - Create Troubleshooting guide for thundernetes

[AmieDD]

Is your feature request related to a problem? Please describe.
A common troubleshooting guide would be helpful for people using thundernetes for common scenarios for specific information pertaining to thundernetes.

Describe the solution you'd like
Add a Troubleshooting guide section for thundernetes.

Describe alternatives you've considered
N/A

Additional context
N/a

[dgkanatsios]

Two items that I can think of:

• what should we do if a GameServer gets stuck? We can advise to kubectl delete gs <Name> since this will take down both the GameServer instance, the corresponding Pod as well as the GameServerDetail CRD instance (in case the game server was allocated). We should explicitly mention not to delete the Pod as this might get the GameServer instance in a "weird" state (even worse if the Pod has active players already)
• better document/script the finalizer section here: https://github.com/PlayFab/thundernetes/blob/39f3c8bb3cb4d4f95d128a9700be72cb1014cd21/docs/FAQ.md#deleting-namespace-thundernetes-system-stuck-in-terminating-state
• we should also explicitly mention not to manually override GameServer.status details as this will create issues during controller reconciliation

Anything else?