Merge pull request #1223 from ARMmbed/AnotherButler-patch-3

Move changes in custom-target-porting.md

Author: Amanda Butler

docs/porting/custom-target-porting.md

@@ -38,7 +38,16 @@ Follow these steps to create a custom port for Mbed OS:
 
 ### Customizing
 
-1. Make changes to `custom_targets.json` for your board. For example, after making changes, the full contents look like this:
+1. Make changes to `custom_targets.json` for your board.
+
+   In this example:
+
+   1. The board name changes from `DISCO_L475VG_IOT01A` to `IMAGINARYBOARD`, so the board can be uniquely identified.
+   1. The `detect_code` changes from `0764` to `1234`. The `detect_code` is a unique four-digit hexadecimal value, also called a `Platform ID`, that identifies the board to the Mbed OS test tools. For Mbed Enabled boards, this number is exposed through the debug interface with Mbed CLI by typing `mbedls`.
+   1. The `macros_add` section changes to remove `USBHOST_OTHER` because the new board does not use USB.
+   1. The `device_has_add` section changes to remove the `ANALOGOUT`, `CAN`, and `USBDEVICE` drivers because the new board doesn't use those features.
+
+   After making changes, the full contents look like this:
 
    ```
    {
@@ -83,15 +92,6 @@ Follow these steps to create a custom port for Mbed OS:
    }
    ```
 
-   Let's review the changes one by one.
-
-#### Changes
-
-1. The board name changed from `DISCO_L475VG_IOT01A` to `IMAGINARYBOARD`, so the board can be uniquely identified.
-1. The `detect_code` changed from `0764` to `1234`. The `detect_code` is a unique four-digit hexadecimal value, also called a `Platform ID`, that identifies the board to the Mbed OS test tools. For Mbed Enabled boards, this number is exposed through the debug interface with Mbed CLI by typing `mbedls`.
-1. The `macros_add` section changed to remove `USBHOST_OTHER` because the new board does not use USB.
-1. The `device_has_add` section was changed to remove the `ANALOGOUT`, `CAN`, and `USBDEVICE` drivers because the new board doesn't use those features.
-
 #### Additions
 
 A new section, `device_has_remove`, was added. This removes the `ANALOGIN`, `I2CSLAVE` and `I2C_ASYNCH` drivers because these features are also not used. The reason why `device_has_remove` is used in this case is because the board is inheriting from the MCU Family configuration `FAMILY_STM32`, which has those drivers added by default.