Ensure tslib.es6.js is typed

Author: andrewbranch

package.json

@@ -28,10 +28,16 @@
     "sideEffects": false,
     "exports": {
         ".": {
-            "module": "./tslib.es6.js",
+            "module": {
+              "types": "./tslib.d.ts",
+              "default": "./tslib.es6.js"
+            },
             "import": {
               "node": "./modules/index.js",
-              "default": "./tslib.es6.js"
+              "default": {
+                "types": "./tslib.d.ts",
+                "default": "./tslib.es6.js"
+              }
             },
             "default": "./tslib.js"
         },