Tweak contributing docs as per feedback

Author: Marcelo Salazar

README.md

@@ -314,12 +314,13 @@ The contribution of platform support to this repository is restricted to Arm Mbe
 Expectations on contributions:
 
 -	No code changes in `main.cpp`.
-This is a minimal and generic application that’s expected to work on out of the box with all platforms listed in the documentation and [Pelion Quick-start](https://os.mbed.com/guides/connect-device-to-pelion/) guide
+This is a minimal and generic application that’s expected to work on out of the box with all platforms listed in the documentation and [Pelion Quick-start](https://os.mbed.com/guides/connect-device-to-pelion/) guide.
 
 - No changes to the hash of `mbed-os.lib ` or `mbed-cloud-client.lib` files.
-These are maintained and updated by the Arm team.
+The Mbed OS release used in this repository should be update-to-date but you can raise an issue to be updated by the maintainers.
 
 -	No extra files or `.mbedignore` with removal of Mbed OS code.
+You may need to fix issues and send a PR to [Mbed OS](https://github.com/ARMmbed/mbed-os) first.
 
 -	Configuration (required)
      - `mbed_app.json` to add components or features. Please follow the guidelines in the porting section of the docs.
@@ -328,22 +329,25 @@ These are maintained and updated by the Arm team.
      -	If required, drivers for networking or storage (non-default) can be added in the `drivers` folder using an external library (.lib). For example  `COMPONENT_MYDRIVER.lib` and enabling in `mbed_app.json`.
 
 -	Bootloader (required)
-     -	The configuration should be provided in either [mbed-bootloader](https://github.com/ARMmbed/mbed-bootloader) repository (as default configuration) or bootloader folder in this repository (if non-default). Our recommendation is to contribute to the mbed-bootloader repository whether possible. Please indicate where the bootloader configuration lives.
-     -	Binaries should be generated and contributed following the name conventions (see bootloader folder).
+     -	The configuration should be provided in either [mbed-bootloader](https://github.com/ARMmbed/mbed-bootloader) repository (as default configuration) or [bootloader](https://github.com/ARMmbed/mbed-os-example-pelion/tree/master/bootloader) folder in this repository (if non-default). Our recommendation is to contribute to the mbed-bootloader repository whether possible. Please indicate where the bootloader configuration lives.
+     -	Binaries should be generated and contributed following the name conventions in the bootloader folder.
 
 -	Indication of platform support
      -	Please update `README.md` file and add an entry to the list of supported boards.
 
 -	Test results and other information
      -	Attach test logs for required toolchains as documented [here](https://os.mbed.com/docs/mbed-os/latest/tools/index.html)
-           -	Greentea (Mbed OS tests, including integration tests) 
+           - Greentea (Mbed OS tests, including integration tests) 
            - Pelion E2E tests based on pytest
      -	Mbed OS and Mbed-cloud-client version used during the tests.
         Note contributions will be accepted only against versions available in the example at that time.
 
 -	Pull-requests are raised against the master branch. The Arm team makes releases regularly.
+
 -	Pelion-Ready. Indicate if a platform is expected to be marked as Pelion-Ready and therefore be added to the Pelion Quick-start
 
+- You agree that the configuration changes contributed are considered open source and Apache 2.0 licensed.
+
 -	Support of the platform is provided by Silicon Partners or Platform vendors for Mbed Enabled platforms. If using a non-default configuration, then Arm is responsible for its support.
 
 Note platforms will be tested regularly in the Arm CI system. Please discuss with your Arm contact and make hardware available as indicated in the Mbed Enabled requirements.