Update Contentful example to add validations to solve graphql complex…

…ity errors. (#33958)

Hi! Dev Rel from Contentful here. We noticed that the Contentful example was giving a graphQL complexity error so adding in some validations to the content model that is imported to prevent the error from showing up. 

## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

examples/cms-contentful/contentful/export.json

@@ -151,7 +151,77 @@
           "type": "RichText",
           "localized": false,
           "required": true,
-          "validations": [],
+          "validations": [
+            {
+              "enabledMarks": ["bold", "italic", "underline", "code"],
+              "message": "Only bold, italic, underline, and code marks are allowed"
+            },
+            {
+              "enabledNodeTypes": [
+                "heading-1",
+                "heading-2",
+                "heading-3",
+                "heading-4",
+                "heading-5",
+                "heading-6",
+                "ordered-list",
+                "unordered-list",
+                "hr",
+                "blockquote",
+                "embedded-entry-block",
+                "embedded-asset-block",
+                "hyperlink",
+                "entry-hyperlink",
+                "asset-hyperlink",
+                "embedded-entry-inline"
+              ],
+              "message": "Only heading 1, heading 2, heading 3, heading 4, heading 5, heading 6, ordered list, unordered list, horizontal rule, quote, block entry, asset, link to Url, link to entry, link to asset, and inline entry nodes are allowed"
+            },
+            {
+              "nodes": {
+                "asset-hyperlink": [
+                  {
+                    "size": {
+                      "max": 10
+                    },
+                    "message": null
+                  }
+                ],
+                "embedded-asset-block": [
+                  {
+                    "size": {
+                      "max": 10
+                    },
+                    "message": null
+                  }
+                ],
+                "embedded-entry-block": [
+                  {
+                    "size": {
+                      "max": 10
+                    },
+                    "message": null
+                  }
+                ],
+                "embedded-entry-inline": [
+                  {
+                    "size": {
+                      "max": 10
+                    },
+                    "message": null
+                  }
+                ],
+                "entry-hyperlink": [
+                  {
+                    "size": {
+                      "max": 10
+                    },
+                    "message": null
+                  }
+                ]
+              }
+            }
+          ],
           "disabled": false,
           "omitted": false
         },