add api extractor config

Author: ChaoqunCHEN

packages-exp/installations-types-exp/api-extractor.json

@@ -0,0 +1,5 @@
+{
+    "extends": "../../config/api-extractor.json",
+    // Point it to your entry point d.ts file. 
+    "mainEntryPointFilePath": "<projectFolder>/index.d.ts"
+}