Merge branch 'develop' of https://labs.etsi.org/rep/osl/documentation into develop

doc/architecture/CRIDGE/CRIDGEforDevelopers.md

doc/architecture/nfvweb.md

doc/config_intro.md

doc/index.md

doc/naas/exposed_apis.md

doc/naas/gst_to_gsma/img01.png

doc/naas/gst_to_tmf.md

doc/naas/introduction.md

doc/naas/lcm/img01.png

doc/naas/lcm/img02.png

doc/naas/lcm/img03.png

doc/naas/lcm_intro.md

doc/naas/lcm_rules_intro.md

doc/naas/nfv/nfvservices.md

doc/naas/resource_catalog.md

doc/naas/service_catalog.md

doc/naas/service_catalog/img01.png

doc/naas/service_inventory.md

doc/naas/service_ordering.md

doc/naas/service_spec.md