resource allocation guideline for k8s

[wey-gu]

Change Request

1. Describe what you find is inappropriate or missing in the existing docs.

We don't have guidelines for k8s users to plan their spec of meta/storage/graphd pods

2. Describe your suggestion or addition.

• Add equivalent things of the bare-metal use case for k8s?

3. Provide some reference materials (documents, websites, etc) if you could.

• https://github.com/vesoft-inc/nebula/discussions/5879

[abby-cyber]

@MegaByte875 Please take a look.