doc/tutorial: update entgql + gqlgen integration (#2915)

doc/md/tutorial-todo-gql-paginate.md

@@ -39,7 +39,7 @@ Cursor Connections interface, read the following paragraphs that were taken from
 
 The code for this tutorial is available under [github.com/a8m/ent-graphql-example](https://github.com/a8m/ent-graphql-example),
 and tagged (using Git) in each step. If you want to skip the basic setup and start with the initial version of the GraphQL
-server, you can clone the repository and checkout `v0.1.0` as follows:
+server, you can clone the repository as follows:
 
 ```console
 git clone git@github.com:a8m/ent-graphql-example.git
@@ -50,9 +50,8 @@ go run ./cmd/todo/
 
 ## Add Annotations To Schema
 
-Ordering can be defined on any comparable field of ent by annotating it with `entgql.Annotation`.
-Note that the given `OrderField` name must match its enum value in GraphQL schema (see
-[next section](#define-ordering-types-in-graphql-schema) below).
+Ordering can be defined on any comparable field of Ent by annotating it with `entgql.Annotation`.
+Note that the given `OrderField` name must be uppercase and match its enum value in the GraphQL schema.
 
 ```go title="ent/schema/todo.go"
 func (Todo) Fields() []ent.Field {
@@ -86,82 +85,25 @@ func (Todo) Fields() []ent.Field {
 }
 ```
 
-## Define Types In GraphQL Schema
-
-Next, we need to add the ordering types along with the [Relay Connection Types](https://relay.dev/graphql/connections.htm#sec-Connection-Types)
-to the GraphQL schema:
-
-```graphql title="todo.graphql"
-# Define a Relay Cursor type:
-# https://relay.dev/graphql/connections.htm#sec-Cursor
-scalar Cursor
-
-type PageInfo {
-    hasNextPage: Boolean!
-    hasPreviousPage: Boolean!
-    startCursor: Cursor
-    endCursor: Cursor
-}
-
-type TodoConnection {
-    totalCount: Int!
-    pageInfo: PageInfo!
-    edges: [TodoEdge]
-}
-
-type TodoEdge {
-    node: Todo
-    cursor: Cursor!
-}
-
-# These enums are matched the entgql annotations in the ent/schema.
-enum TodoOrderField {
-    CREATED_AT
-    PRIORITY
-    STATUS
-    TEXT
-}
-
-enum OrderDirection {
-    ASC
-    DESC
-}
-
-input TodoOrder {
-    direction: OrderDirection!
-    field: TodoOrderField
-}
-```
-
-Note that the naming must take the form of `<T>OrderField` / `<T>Order` for `autobind`ing to the generated ent types.
-Alternatively [@goModel](https://gqlgen.com/config/#inline-config-with-directives) directive can be used for manual type binding.
-
 ## Add Pagination Support For Query
 
-```graphql
-type Query {
-    todos(
-        after: Cursor
-        first: Int
-        before: Cursor
-        last: Int
-        orderBy: TodoOrder
-    ): TodoConnection!
+1\. The next step for enabling pagination is to tell Ent that the `Todo` type is a Relay Connection.
+
+```go title="ent/schema/todo.go"
+func (Todo) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+        //highlight-next-line
+		entgql.RelayConnection(),
+		entgql.QueryField(),
+		entgql.Mutations(entgql.MutationCreate()),
+	}
 }
 ```
-That's all for the GraphQL schema changes, let's run `gqlgen` code generation.
 
-## Update The GraphQL Resolver
+2\. Then, run `go generate .` and you'll notice that `ent.resolvers.go` was changed. Head over to the `Todos` resolver
+and update it to pass pagination arguments to `.Paginate()`:
 
-After changing our Ent and GraphQL schemas, we're ready to run the codegen and use the `Paginate` API:
-
-```console
-go generate ./...
-```
-
-Head over to the `Todos` resolver and update it to pass `orderBy` argument to `.Paginate()` call:
-
-```go title="todo.resolvers.go"
+```go title="ent.resolvers.go" {2-5}
 func (r *queryResolver) Todos(ctx context.Context, after *ent.Cursor, first *int, before *ent.Cursor, last *int, orderBy *ent.TodoOrder) (*ent.TodoConnection, error) {
 	return r.client.Todo.Query().
 		Paginate(ctx, after, first, before, last,
@@ -210,7 +152,7 @@ query {
 # Output: { "data": { "todos": { "edges": [ { "node": { "id": "16", "text": "Create GraphQL Example" }, "cursor": "gqFpEKF2tkNyZWF0ZSBHcmFwaFFMIEV4YW1wbGU" }, { "node": { "id": "15", "text": "Create GraphQL Example" }, "cursor": "gqFpD6F2tkNyZWF0ZSBHcmFwaFFMIEV4YW1wbGU" }, { "node": { "id": "14", "text": "Create GraphQL Example" }, "cursor": "gqFpDqF2tkNyZWF0ZSBHcmFwaFFMIEV4YW1wbGU" } ] } } }
 ```
 
-We can also use the cursor we got in the query above to get all items after that cursor:
+We can also use the cursor we got in the query above to get all items that come after it.
 
 ```graphql
 query {
@@ -230,5 +172,5 @@ query {
 
 ---
 
-Great! With a few simple changes, our application now supports pagination! Please continue to the next section where we explain how to implement GraphQL field collections and learn how Ent solves
-the *"N+1 problem"* in GraphQL resolvers.
+Great! With a few simple changes, our application now supports pagination. Please continue to the next section where we
+explain how to implement GraphQL field collections and learn how Ent solves the *"N+1 problem"* in GraphQL resolvers.