Add TypeScript config for @mailpoet/components

This handles both type checking and type declaration emitting.

[MAILPOET-5015]

packages/js/components/.gitignore

@@ -1,2 +1,3 @@
 /build
 /build-module
+/build-types

packages/js/components/package.json

@@ -10,6 +10,7 @@
       "import": "./build-module/index.js"
     }
   },
+  "types": "build-types/index.d.ts",
   "scripts": {
     "build": "wp-scripts build",
     "start": "wp-scripts start"
@@ -21,6 +22,7 @@
   "devDependencies": {
     "@types/react": "18.0.28",
     "@types/react-dom": "18.0.11",
+    "fork-ts-checker-webpack-plugin": "^7.2.1",
     "react": "^18.2.0",
     "react-dom": "^18.2.0"
   },

packages/js/components/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "include": ["src/**/*"],
+  "compilerOptions": {
+    "rootDir": "src",
+    "declaration": true,
+    "emitDeclarationOnly": true,
+    "outDir": "build-types"
+  }
+}

packages/js/components/webpack.config.js

@@ -1,5 +1,6 @@
 import path from 'node:path';
 import { default as defaultConfig } from '@wordpress/scripts/config/webpack.config.js';
+import ForkTsCheckerWebpackPlugin from 'fork-ts-checker-webpack-plugin';
 import { WebpackEmitAllPlugin } from '../../../tools/webpack/webpack-emit-all-plugin.js';
 
 const dirname = new URL('.', import.meta.url).pathname;
@@ -9,6 +10,7 @@ const plugins = [
     (plugin) => plugin.constructor.name !== 'DependencyExtractionWebpackPlugin',
   ),
   new WebpackEmitAllPlugin({ context: path.join(dirname, 'src') }),
+  new ForkTsCheckerWebpackPlugin({ typescript: { mode: 'write-dts' } }),
 ];
 
 export default {