feat: package is now ESM (#545)

BREAKING CHANGE: package is now ESM

README.md

@@ -32,8 +32,8 @@ Node
 Install with `npm install @octokit/core @octokit/plugin-enterprise-cloud`. Optionally replace `@octokit/core` with a core-compatible module
 
 ```js
-const { Octokit } = require("@octokit/core");
-const { enterpriseCloud } = require("@octokit/plugin-enterprise-cloud");
+import { Octokit } from "@octokit/core";
+import { enterpriseCloud } from "@octokit/plugin-enterprise-cloud";
 ```
 
 </td></tr>
@@ -49,6 +49,12 @@ octokit.scim.listProvisionedIdentities({
 });
 ```
 
+> [!IMPORTANT]
+> As we use [conditional exports](https://nodejs.org/api/packages.html#conditional-exports), you will need to adapt your `tsconfig.json` by setting `"moduleResolution": "node16", "module": "node16"`.
+>
+> See the TypeScript docs on [package.json "exports"](https://www.typescriptlang.org/docs/handbook/modules/reference.html#packagejson-exports).<br>
+> See this [helpful guide on transitioning to ESM](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c) from [@sindresorhus](https://github.com/sindresorhus)
+
 ## How it works
 
 The GitHub Enterprise Cloud route definitions are build automatically from [`@octokit/routes`](https://github.com/octokit/routes). Each time there is a new `@octokit/routes` release, the [`.github/workflows/routes-update.yml`](.github/workflows/routes-update.yml) workflow is triggered. If an update to [`routes.json`](routes.json) is found, a pull request is created.