docs: update

Author: Ansonhkg

lit-actions-ts-bundling/README.md

@@ -26,7 +26,7 @@ import { code } from "./lit-actions/dist/hello-world.js";
 console.log("litActionCode:", code);
 ```
 
-## output
+## Output
 
 ```
 npm run build
@@ -38,4 +38,20 @@ npm run build
    Size: 0.0251 MB (decimal) | 0.0239 MB (binary)
 ================================================
 ✅ Lit actions built successfully in 0.02 seconds
+```
+
+## Features
+
+### Lit Action global variables type definition
+
+![](https://private-user-images.githubusercontent.com/4049673/378098250-19ef8b19-4b98-441b-b169-59a4f777131d.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.fqIXjfuEGGsx3htuQeroMnixM9L1Jtk5J1SipOn03HE)
+
+## shim js file from the header
+
+```ts
+/**
+ * My hello world Lit Action
+ * 
+ * inject ./buffer.shim.js
+ */
 ```