Update desktop/README.md describing the embed mode config (#587)

packages/desktop/README.md

@@ -24,7 +24,7 @@ Convert your [Streamlit](https://streamlit.io/) application into a desktop app w
        }
      },
      "devDependencies": {
-       "@stlite/desktop": "0.34.0",
+       "@stlite/desktop": "0.36.0",
        "cross-env": "^7.0.3",
        "electron": "^25.2.0",
        "electron-builder": "^24.4.0"
@@ -56,6 +56,21 @@ Convert your [Streamlit](https://streamlit.io/) application into a desktop app w
 To make your app secure, be sure to use the latest version of Electron.
 This is [announced](https://www.electronjs.org/docs/latest/tutorial/security#16-use-a-current-version-of-electron) as one of the security best practices in the Electron document too.
 
+## Hide the toolbar, hamburger menu, and the footer
+
+If you want to hide the toolbar, hamburger menu, and the footer, add the following to your `package.json` file and run the `dump` command again. By adding the `stlite.desktop.embed` field, the dumped Streamlit app will work in the [embed mode](https://docs.streamlit.io/streamlit-community-cloud/get-started/embed-your-app#embedding-with-iframes) which hides the toolbar, hamburger menu, and the footer.
+
+```json
+{
+  // ...other fields...
+  "stlite": {
+    "desktop": {
+      "embed": true
+    }
+  }
+}
+```
+
 ## Limitations
 
 - Navigation to external resources like `st.markdown("[link](https://streamlit.io/)")` does not work for security. See https://github.com/whitphx/stlite/pull/445 and let us know if you have use cases where you have to use such external links.