Setup a CI job to build and commit devfile documentation

[mshaposhnik]

Description

To publish actual devfile docs (#12524), we need separate CI job, which will (ideally after each release)
build those docs and push them to the github.io page.

Details:

Build:

Execute build of che/wsmaster/che-api-devfile with enabled profile:
-Pdevfile-docs-docker - to build in docker;
or
-Pdevfile-docs-native - to build as native nodejs app;

Commit:

Previous step will produce the docs folder in target of the che-api-devfile module,
contents of which should be pushed to:
https://github.com/redhat-developer/devfile/ repo into docs folder.

Result:

Docs shold be renewed at https://redhat-developer.github.io/devfile/