Add v1 -> v2 migration instructions

Author: Maximization

README.md

@@ -6,6 +6,11 @@ Find an overview of what rules are enabled, and why, in this article:
 
 📚 [**14 Linting Rules To Help You Write Asynchronous Code in JavaScript**](https://maximorlov.com/linting-rules-for-asynchronous-code-in-javascript/)
 
+## Table of contents
+
+- [Installation & usage](#installation--usage)
+- [Migrating from v1 to v2](#migrating-from-v1-to-v2)
+
 ## Installation & usage
 
 ### Base rules
@@ -73,3 +78,53 @@ module.exports = {
   }
 };
 ```
+
+## Migrating from v1 to v2
+
+Version 2 adds TypeScript specific rules and exports multiple configs, namely:
+
+- Base rules (`eslint-config-async`)
+- Node.js specific rules (`eslint-config-async/node`)
+- TypeScript rules (`eslint-config-async/typescript`)
+
+In version 1, the base and Node.js specific rules were included by default. In version 2, you need to explicitly add the Node.js rules:
+
+```diff
+module.exports = {
+  extends: [
+-   'eslint-config-async'
++   'eslint-config-async',
++   'eslint-config-async/node'
+  ],
+}
+```
+
+Or using the short syntax:
+
+```diff
+module.exports = {
+  extends: [
+-   'eslint-config-async'
++   'async',
++   'async/node'
+  ],
+}
+```
+
+If you added the TypeScript specific rules manually in your project, you can remove them and replace them with this config:
+
+```diff
+module.exports = {
+  extends: [
+    'async',
+    'async/node',
++   'async/typescript'
+  ],
+  rules: {
+-   "@typescript-eslint/await-thenable": "error",
+-   "@typescript-eslint/no-floating-promises": "error",
+-   "@typescript-eslint/no-misused-promises": "error",
+-   "@typescript-eslint/promise-function-async": "error",
+  }
+}
+```