Document the TokenRateLimitPolicy

[david-martin]

• Reference pages

• Tutorial &/or Guide for either/both

• Include how to use it and an an AuthPolicy
  See the RFC example API

    ```yaml
    apiVersion: kuadrant.io/v1
    kind: AuthPolicy
    metadata:
      name: free-users-auth
    spec:
      targetRef:
        group: gateway.networking.k8s.io
        kind: Gateway
        name: my-llm-gateway
      rules:
        authorization:
          "free-users":
            opa:
              rego: |
                groups := split(object.get(input.auth.identity.metadata.annotations, "kuadrant.io/groups", ""), ",")
                allow { groups[_] == "free" }
    ---
    apiVersion: v1
    kind: Secret
    metadata:
      name: api-key-free-user-1
        app: my-llm
      annotations:
        kuadrant.io/groups: free
        secret.kuadrant.io/user-id: user-1
    stringData:
      api_key: iamafreeuser
    type: Opaque
    ---
    apiVersion: kuadrant.io/v1alpha1
    kind: TokenRateLimitPolicy
    metadata:
      name: token-limit-free
    spec:
      targetRef:
        group: gateway.networking.k8s.io
        kind: Gateway
        name: my-llm-gateway
      limit:
        rate:
          limit: 20000
          window: 1d
        predicate: 'request.auth.claims["kuadrant.io/groups"].split(",").exists(g, g == "free")' 
        counter: auth.identity.userid
    ```
  

• Also consider a blog post to announce

Pull Requests:

• TRLP tutorial + reference #1410
• trlp blog post - announcement kuadrant.github.io#79
• Adding TokenRateLimitPolicy ref + tutorial docs.kuadrant.io#205

[jasonmadigan]

cc: @maleck13

[jasonmadigan]

👀

[jasonmadigan]

draft guide linked

added a note to write a small blog post to announce as well