Use alternative strategy that works better for ESM builds

Add a new top-level export map entry for `initializeProvider` that maps
correctly onto CJS and ESM builds, and add a fallback JavaScript file
at the root of the repository for build systems that don't support
export maps.

This gives the best of both worlds: build systems that support exports
will behave correctly, and those that don't will get the CJS fallback.

initializeInpageProvider.d.ts

@@ -0,0 +1,3 @@
+// Re-exported for compatibility with build tools that don't support the
+// `exports` field in package.json
+export * from './dist/initializeInpageProvider.cjs';

initializeInpageProvider.js

@@ -0,0 +1,3 @@
+// Re-exported for compatibility with build tools that don't support the
+// `exports` field in package.json
+module.exports = require('./dist/initializeInpageProvider.cjs');

package.json

@@ -49,10 +49,6 @@
         "default": "./dist/initializeInpageProvider.cjs"
       }
     },
-    "./dist/initializeInpageProvider.cjs": {
-      "types": "./dist/initializeInpageProvider.d.cts",
-      "default": "./dist/initializeInpageProvider.cjs"
-    },
     "./stream-provider": {
       "import": {
         "types": "./dist/StreamProvider.d.mts",
@@ -70,6 +66,8 @@
   "types": "./dist/index.d.cts",
   "files": [
     "dist",
+    "initializeInpageProvider.d.ts",
+    "initializeInpageProvider.js",
     "stream-provider.js"
   ],
   "scripts": {