Update the ReadMe file to introduce the basic configuration and usage of the notification service

Author: lexuanzhou001

README.md

@@ -9,8 +9,63 @@ This module integrates web push notification services into applications using th
 # Getting Started
 To implement this module in your ABP framework application, @<Lexuan Zhou> TBD... Ensure to configure the necessary dependencies and integrate the service with your application's frontend and backend.
 
-# Contribution
+# Configuration
+Step 1:
+
+1. Install the [WebPushNotificationService ABP Framework Module](https://github.com/DecisionTreeTechnology/WebPushNotificationService) from Nuget into your project
+
+2. Add DependsOn(typeof(WebPushxxxModule)) attribute to configure the module dependencies.
+
+3. Add ```builder.ConfigureWebPush();``` to the OnModelCreating() method in ```MyProjectMigrationsDbContext.cs```.
+
+4. Add EF Core migrations and update your database.  The service will rely on three table to retrive and push notifications: ```WebPushContents```, ```WebPushSubscriptions``` and ```WebPushNotifications```
+
+
+Step 2:
+
+A pair of VAPID key is needed for the system (what is [VAPID Key](https://stackoverflow.com/questions/40392257/what-is-vapid-and-why-is-it-useful) 🤔). There are multiple ways to generate them. 
+
+For Angular:
+
+- Install the [web-push](https://www.npmjs.com/package/web-push) package from NPM by running ```npm install web-push -g```
+- Generate the vapid keys by running ```web-push generate-vapid-keys [--json]```. An example of a pair of VAPID Keys would be 
+
+```
+Public Key:
+BFwNomlUWWD2-wDR1cLhPQOxFskYDuUmseG_Pvi2DWI8eMMQuQufq27cQWa_tpO9sGK-AxRrKLdM2YLtdHTW1Dc
+
+Private Key:
+Ycpv7MDLJpB9512dZoQ6m2puX6tlnhMoKVtydY0Lz94
+```
+
+
+Step 3:
+
+Set up the configuration by putting the pair of VAPID Keys into your application appsettings.json file. The structure of the key value pair would be as follow:
+
+```
+"WebPush": {
+    "VapidKeys": {
+      "PublicKey": "YOUR-PUBLIC-KEY",
+      "PrivateKey": "YOUR-PUBLIC-KEY"
+    },
+    "Email": "YOUR-EMAIL"
+  }
+```
+
+# Usuage
+Create a ETO (event trasfer object) and push it to the event bus and it will handle the notification queue under the hood
+```
+var pushNotificationEto = 
+        new CreateWebPushNotificationEto(CurrentTenant.Id, new List<Guid>{createMessageInput.ToUserId}, createMessageInput.Subject, 
+            null, null, null, null, new DateTime?(), null);
+await _distributedEventBus.PublishAsync(pushNotificationEto);
+```
+
+
+
+
 Contributions are welcome! If you have suggestions or improvements, please fork the repository and submit a pull request.
 
 # License
-This project is licensed under the MIT License - see the LICENSE file for details.
+This project is licensed under the MIT License - see the LICENSE file for details.