Fix module resolver alias to work on Windows again

Author: tilgovi

babel.config.js

@@ -53,7 +53,8 @@ module.exports = (api) => {
     ...(DEV || TEST
       ? {
           alias: {
-            '^@apache-annotator/([^/]+)$': `${packagePath}/\\1/src/index.ts`,
+            '^@apache-annotator/([^/]+)$': ([, name]) =>
+              path.join(packagePath, name, 'src', 'index.ts'),
           },
           resolvePath(sourcePath, currentFile, opts) {
             if (