Merge branch 'OCF-Doc4-upgrade-documentation-with-new-tests' into 'develop'

doc/architecture.md

doc/images/logo_osl.png

doc/images/logo_osl_square.png

doc/images/logo_osl_square_non_transp.png

doc/images/openslice_logo.png

doc/images/openslice_logo_old.png

doc/index.md

doc/releasenotes.md

doc/testing/robotframework/README.md

doc/testing/testplan/README.md

doc/testing/testplan/api_access_control_policy/README.md

doc/testing/testplan/api_auditing_service/README.md

doc/testing/testplan/api_discover_service/README.md

doc/testing/testplan/api_events_service/README.md

doc/testing/testplan/api_invoker_management/README.md

...estplan/api_invoker_management/invoker_register_body.json

doc/testing/testplan/api_logging_service/README.md

doc/testing/testplan/api_provider_management/README.md

...tplan/api_provider_management/provider_register_body.json

doc/testing/testplan/api_publish_service/README.md