docs(README): update examples to use ESM (#611)

Author: wolfy1339

README.md

@@ -33,11 +33,11 @@ Node
 Install with `npm install @octokit/core @octokit/plugin-paginate-rest`. Optionally replace `@octokit/core` with a core-compatible module
 
 ```js
-const { Octokit } = require("@octokit/core");
-const {
+import { Octokit } from "@octokit/core";
+import {
   paginateRest,
   composePaginateRest,
-} = require("@octokit/plugin-paginate-rest");
+} from "@octokit/plugin-paginate-rest";
 ```
 
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