Step by step navigation: adding documentation

[Garneauma]

Adding .gc-stp-stp documentation and example.

[duboisp]

Would you like to create a include for this component and to update the "advanced service" template to use that include?

And I can see there is new CSS added for this component, is that necessary or probably a minor/patch change to the component?

[duboisp]

Pre-approved upon review and local testing.

To be confirm: The CSS code for the download link might need to be removed as it was already moved I think.

[Garneauma]

Removed the .gc-dwnld CSS. It was added by mistake during merge conflict resolution.

[duboisp]

Review and tested locally,

Work as expected.

This is a minor change because it add another supported pattern for the gc step step which is the same as the version 1 but simpler to code for an author.