change/API! ~ add package 'exports' to publicize ESM support

- reveals ESM wrapper providing ESM support (as suggested in "Node Modules at War")

* ref: [Node Modules at War](https://redfin.engineering/node-modules-at-war-why-commonjs-and-es-modules-cant-get-along-9617135eeca1) @@ <https://archive.is/zl0qg>
* ref: [yargs ~ 'Road to ESM/Deno'](yargs/yargs#1706).

package.json

@@ -17,8 +17,23 @@
 		"LICENSE",
 		"README.md"
 	],
-	"main": "src/lib/index.js",
-	"types": "src/lib/index.d.ts",
+	"type": "commonjs",
+	"main": "./dist/cjs/mod.cjs.js",
+	"module": "./dist/cjs/esm-wrapper/mod.esm.js",
+	"types": "./dist/types/mod.d.ts",
+	"exports": {
+		".": {
+			"import": "./dist/cjs/esm-wrapper/mod.esm.js",
+			"require": "./dist/cjs/mod.cjs.js",
+			"types": "./dist/types/mod.d.ts",
+			"default": "./dist/cjs/mod.cjs.js"
+		},
+		"./package.json": "./package.json",
+		"./cjs": {
+			"require": "./dist/cjs/mod.cjs.js",
+			"types": "./dist/cjs/mod.cjs.d.ts"
+		}
+	},
 	"keywords": [
 		"appdir",
 		"application",