add schema

- copied from https://www.apollographql.com/docs/apollo-server/example.html

Author: Johnwook Choi

schema.ts

@@ -0,0 +1,32 @@
+import { makeExecutableSchema } from "graphql-tools";
+
+// Some fake data
+const books = [
+  {
+    author: "J.K. Rowling",
+    title: "Harry Potter and the Sorcerer's stone"
+  },
+  {
+    author: "Michael Crichton",
+    title: "Jurassic Park"
+  }
+];
+
+// The GraphQL schema in string form
+const typeDefs = `
+  type Query { books: [Book] }
+  type Book { title: String, author: String }
+`;
+
+// The resolvers
+const resolvers = {
+  Query: { books: () => books }
+};
+
+// Put together a schema
+const schema = makeExecutableSchema({
+  resolvers,
+  typeDefs
+});
+
+export default schema;