CMake: Specify mbedtools in the build instructions

mbedtools provides a more user friendly UX for
building application.

Author: hugueskamba

tools/cmake/README.md

@@ -45,21 +45,18 @@ Prerequisities:
 - CMake >=3.19.0
 - mbed-tools >=3.4.0
 
-From the application root or wherever `mbed-os.lib` is found:
-1. Run the following command to create the Mbed OS configuration CMake module: 
+From the application root or wherever `mbed-os.lib` is found, run the following command to:
+ * create the Mbed OS configuration CMake module
+ * create a build directory
+ * generate the project configuration
+ * build the project using the `Ninja` build system
 
     ```
-    mbedtools configure -m <mbed-target> -t <toolchain>
+    mbedtools build -m <mbed-target> -t <toolchain>
     ```
 
-1. Run the following command to create a build directory, generate the project configuration and build the project using `Ninja`: 
-
-    ```
-    mkdir build && cd build && cmake .. -GNinja && cmake --build .
-    ```
-
-The default build type is `Develop`. Use `CMAKE_BUILD_TYPE` to select `Develop`, `Release` or `Debug` as follows: 
+The default build type is `Develop`. Use the `--build-type` optional argument of the `build` subcommand to select `Develop`, `Release` or `Debug` as follows: 
 
 ```
-cmake .. -GNinja -DCMAKE_BUILD_TYPE=<supported-build-type> && cmake --build .
+mbedtools build -m <mbed-target> -t <toolchain> -b <supported-build-type>
 ```