[Documentation]: GPU service docs don't mention the "eidf/user" metadata requirement

[rupertnash]

What documentation issue are you reporting

No response

Issue

When using the example file in https://docs.eidf.ac.uk/services/gpuservice/training/L2_requesting_persistent_volumes/
I am told:

The persistentvolumeclaims "test-pvc-rwn" is invalid: : ValidatingAdmissionPolicy 'label-user-validating-admission-policy' with binding 'label-validating-admission-policy-binding' denied request: The metadata label 'eidf/user' is missing or has an empty value set.

Adding the label works fine, but this might throw off newer users

[agngrant]

This requirement isn't enabled on all projects, only projects which have requested it. This is why it doesn't appear in the main documentation. Projects which have it enabled have internal guidelines and notifications around its use. If you think it should be part of the documentation, let us know.

[rupertnash]

Thanks @agngrant, I take your point, but how would a user find this out? You are depending on project PIs to document this well enough that their users can find it. (I only knew what to look for as my student had mentioned it in passing, as the project mailing was in my holiday backlog)