chore(search-react): configure alpha subpath

Signed-off-by: Camila Belo <camilaibs@gmail.com>

plugins/search-react/package.json

@@ -5,9 +5,22 @@
   "types": "src/index.ts",
   "license": "Apache-2.0",
   "publishConfig": {
-    "access": "public",
-    "main": "dist/index.esm.js",
-    "types": "dist/index.d.ts"
+    "access": "public"
+  },
+  "exports": {
+    ".": "./src/index.ts",
+    "./alpha": "./src/alpha.ts",
+    "./package.json": "./package.json"
+  },
+  "typesVersions": {
+    "*": {
+      "alpha": [
+        "src/alpha.ts"
+      ],
+      "package.json": [
+        "package.json"
+      ]
+    }
   },
   "backstage": {
     "role": "web-library"

plugins/search-react/src/alpha.ts

@@ -0,0 +1,15 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */