Distribute package as both ESM and CJS (#25)

package.json

@@ -1,12 +1,20 @@
 {
   "name": "kysely-d1",
   "description": "Kysely dialect for Cloudflare D1",
-  "main": "./dist/index.js",
+  "main": "./dist/index.cjs",
+  "module": "./dist/index.js",
   "version": "0.3.0",
   "types": "./dist/index.d.ts",
   "repository": "[email protected]:aidenwallis/kysely-d1.git",
   "author": "Aiden <[email protected]>",
   "license": "MIT",
+  "type": "module",
+  "exports": {
+    ".": {
+      "import": "./dist/index.js",
+      "require": "./dist/index.cjs"
+    }
+  },
   "files": [
     "dist"
   ],
@@ -18,7 +26,7 @@
     "serverless"
   ],
   "scripts": {
-    "build": "tsc",
+    "build": "tsc && tsc -p tsconfig.cjs.json && mv dist/cjs/index.js dist/index.cjs && rmdir dist/cjs",
     "check": "prettier --check src/ example/",
     "format": "prettier --write src/ example/"
   },

tsconfig.cjs.json

@@ -0,0 +1,8 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "module": "CommonJS",
+    "outDir": "dist/cjs",
+    "declaration": false
+  }
+}

tsconfig.json

@@ -2,6 +2,7 @@
   "extends": "@tsconfig/node14/tsconfig.json",
   "compilerOptions": {
     "rootDir": "src",
+    "module": "ESNext",
     "outDir": "dist",
     "alwaysStrict": true,
     "skipLibCheck": true,