type Post
    @model
    @auth(rules: [{ allow: owner }]) {
    id: ID!
    postBody: String!
    pictureKey: String!
    createdAt: AWSDateTime!
    postedBy: User @belongsTo
}

type User
    @model
    @auth(rules: [{ allow: owner }]) {
    id: ID!
    username: String!
    profilePic: String!
    posts: [Post] @hasMany
}