chore(docs): adjust Contentful Rich Text example codes (#29029)

Author: axe312ger

packages/gatsby-source-contentful/README.md

@@ -363,29 +363,30 @@ Rich Text feature is supported in this source plugin, you can use the following
 ### Query Rich Text content and references
 
 ```graphql
-{
- allContentfulBlogPost {
- edges {
- node {
- bodyRichText {
- raw
- references {
- ... on ContentfulAsset {
- contentful_id
- fixed(width: 1600) {
- width
- height
- src
- srcSet
- }
- }
- ... on ContentfulBlogPost {
- contentful_id
- title
- slug
- }
+query pageQuery($id: String!) {
+ contentfulBlogPost(id: { eq: $id }) {
+ title
+ slug
+ # This is the rich text field
+ bodyRichText {
+ raw
+ references {
+ ... on ContentfulAsset {
+ contentful_id
+ __typename
+ fixed(width: 1600) {
+ width
+ height
+ src
+ srcSet
  }
  }
+ ... on ContentfulBlogPost {
+ contentful_id
+ __typename
+ title
+ slug
+ }
  }
  }
  }
@@ -420,7 +421,7 @@ const options = {
  },
 }
 
-function BlogPostTemplate({ data, pageContext }) {
+function BlogPostTemplate({ data }) {
  const { bodyRichText } = data.contentfulBlogPost
 
  return <div>{bodyRichText && renderRichText(richTextField, options)}</div>