chore: Update Readme

Author: szuperaz

README.md

@@ -77,8 +77,12 @@ STREAM_USER_ID=<Your user ID>
 STREAM_USER_TOKEN=<Your user token>
 ```
 
+Run `npm install` to install dependencies.
+
 Run `npm start` and navigate to `http://localhost:4200/`.
 
+Preferred Node version: v16.
+
 ## Customization examples
 
 This repository includes a sample app that showcases how you can provide your own template for different components within the SDK:
@@ -93,14 +97,32 @@ STREAM_USER_ID=<Your user ID>
 STREAM_USER_TOKEN=<Your user token>
 ```
 
+Run `npm install` to install dependencies.
+
 Run `npm start:customizations-example` and navigate to `http://localhost:4200/`.
 
+Preferred Node version: v16.
+
 ## Local development
 
+This repository includes a sample app to test our library.
+
+To test the app:
+
+Create a file named `.env` in the root directory with the following content:
+
+```
+STREAM_API_KEY=<Your API key>
+STREAM_USER_ID=<Your user ID>
+STREAM_USER_TOKEN=<Your user token>
+```
+
 Run `npm install` in the root of the project. You can use the `npm run start:dev` command to start the SampleApp with automatic reloading.
 
 A note about the documentation:
 
 - Documentations for Angular services are generated from doc comments in the source files (not under source control)
 - Documentations for inputs and outputs of Angular components are generated from doc comments in the source files (not under source control)
 - Everything else in the documentation is written in `mdx` files located in the `docusaurus` folder
+
+Preferred Node version: v16.