chore(docs): minor typos in tutorial (#1396)

Author: oldo

website/content/010-getting-started/03-tutorial/04-chapter-3-adding-mutations-to-your-api.mdx

@@ -166,7 +166,7 @@ Mutation {
 
 ## Model the domain: Part 2
 
-Before we wrap this chapter let's flush out our schema a bit more. We'll add a `publish` mutation to transform a draft into an actual published post, then we'll let API clients read the the published posts.
+Before we wrap this chapter let's flesh out our schema a bit more. We'll add a `publish` mutation to transform a draft into an actual published post, then we'll let API clients read the published posts.
 
 ```ts
 // api/graphql/Post.ts