SMS Sender document revised.

docs/en/SMS-Sending.md

@@ -2,7 +2,6 @@
 
 The ABP Framework provides an abstraction to sending SMS. Having such an abstraction has some benefits;
 
-- You can **easily integrate** to your favorite SMS sender with a few lines of configuration.
 - You can then **easily change** your SMS sender without changing your application code.
 - If you want to create **reusable application modules**, you don't need to make assumption about how the SMS are sent.
 
@@ -44,7 +43,7 @@ public class YourModule : AbpModule
 
 [Inject](Dependency-Injection.md) the `ISmsSender` into any service and use the `SendAsync` method to send a SMS.
 
-**Example**
+**Example:**
 
 ```csharp
 using System.Threading.Tasks;
@@ -66,35 +65,28 @@ namespace MyProject
         {
             await _smsSender.SendAsync(
                 "+012345678901",        // target phone number
-                "This is test sms..."   // SMS text
+                "This is test sms..."   // message text
             );
         }
     }
 }
 ```
 
-The given `SendAsync` method in the example is an extension method to send sms with primitive paremeters, it basicly creates `SmsMessage` object and pass it. You can also use the default `SendAsync` method which requires `SmsMessage` object.
+The given `SendAsync` method in the example is an extension method to send an SMS with primitive parameters. In addition, you can pass an `SmsMessage` object which has the following properties:
 
-> `ISmsSender` is the suggested way to send SMS, since it makes your code provider independent.
-
-## SmsMessage
-
-In addition to use primitive parameters, you can pass a `SmsMessage` object to the `SendAsync` method.
-
-- `PhoneNumber` (string): Target phone number to send sms.
-- `Text` (string): SMS Text
-- `Properties` (Dictionary<string, string>): string key-value pair to handle different usages by senders.
+- `PhoneNumber` (`string`): Target phone number
+- `Text` (`string`): Message text
+- `Properties` (`Dictionary<string, string>`): Key-value pairs to pass custom arguments
 
 ## NullSmsSender
 
-`NullSmsSender` is a built-in class that implements the `ISmsSender`, but writes sms contents to the [standard log system](Logging.md), rathen than actually sending the SMSs.
+`NullSmsSender` is a the default implementation of the `ISmsSender`. It writes SMS content to the [standard logler](Logging.md), rather than actually sending the SMS.
 
-This class can be useful especially in development time where you generally don't want to send real sms.
-`NullSmsSender` will try to register itself automatically if there is no other registrated sms sender.
+This class can be useful especially in development time where you generally don't want to send real SMS. **However, if you want to actually send SMS, you should implement the `IsSmsSender` in your application code.**
 
-## Creating a custom SMS sender
+## Implementing the ISmsSender
 
-You can easily create your custom provider by creating a class that implements the `ISmsSender` interface.
+You can easily create your SMS sending implementation by creating a class that implements the `ISmsSender` interface, as shown below:
 
 ```csharp
 using System.IO;
@@ -114,8 +106,6 @@ namespace AbpDemo
 }
 ```
 
-That's all. Now you can send SMS by using `MyCustomSmsSender` in your application.
-
-## See also
+## More
 
-- [Twilio SMS Sender](https://docs.abp.io/en/commercial/latest/modules/twilio-sms) with [ABP Commercial](https://commercial.abp.io/).
+[ABP Commercial](https://commercial.abp.io/) provides Twilio integration package to send SMS over [Twilio service](https://docs.abp.io/en/commercial/latest/modules/twilio-sms).

docs/en/docs-nav.json

@@ -285,6 +285,10 @@
             }
           ]
         },
+        {
+          "text": "SMS Sending",
+          "path": "SMS-Sending.md"
+        },
         {
           "text": "Event Bus",
           "items": [