Cleaned up LKE Cluster Create endpoint

The CLI didn't like how the spec was formatted initially, and I'm pretty
sure it was wrong.  This works with the linked CLI PR, but please verify
it looks good in the docs - I'm happy to work with someone to get this
into a mergable state.

Author: Dorthu

openapi.yaml

@@ -6050,10 +6050,6 @@ paths:
               - node_pools
               allOf:
               - $ref: '#/components/schemas/LKEClusterRequestBody'
-              properties:
-                node_pools:
-                  allOf:
-                    - $ref: '#/components/schemas/LKENodePoolRequestBody'
       responses:
         '200':
           description: Kubernetes cluster creation has started.
@@ -15572,6 +15568,10 @@ components:
           example:
           - ecomm
           - blogs
+        node_pools:
+          type: array
+          items:
+            $ref: '#/components/schemas/LKENodePoolRequestBody'
       required:
       - label
       - region
@@ -15628,6 +15628,7 @@ components:
         cluster.
       properties:
         type:
+          type: string
           description: A Linode Type for all of the nodes in the Node Pool.
           example: "g6-standard-4"
         count: