Remove the stale example/ directory

[timflannagan]

Description

Quick cleanup PR that removes the stale (or at least appears to be stale going forward) example/ directory.

Context

Noticed this while researching #10423.

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

[timflannagan]

There's some references to this example directory in the docs/ directory. I held off on purging those since the docs/ directory is another cleanup target and we can tackle that over time.

[nfuden]

How would you feel about stubbing out this directory and adding a README? I like the concept of examples

[timflannagan]

@nfuden Not a bad idea, although it feels a bit premature given overlap with the docs site + test/e2e YAML examples. I can create a tracker for boostrapping a proper example/ directory and seeing what should live there? WYDT?

[yuval-k]

note that we have ggv2 examples https://github.com/k8sgateway/k8sgateway/tree/main/projects/gateway2/examples