Formal specs for CC API V3 enabling automated client generation & API ecosystem tooling

Issue

As an CAPI user

• in order to leverage off-the-shelf API ecosystem tooling (API Web clients, API SDK, Pen testing tools ...)
• I need CAPI to publish API documentation into a standard API specification processable by machine (typically openAPI)

Context

This enhancement request was tracked since 2015 on https://github.com/cloudfoundry/cc-api-v3-style-guide/issues/46 and postponed until CAPI V3 is out.

Reopening this issue since https://github.com/cloudfoundry/cc-api-v3-style-guide repo was archived on April 9th, 2021

Experimental community swagger CAPI V2 API specifications was contributed in the past at https://github.com/cloudfoundry-attic/cf-swagger

This was also requested in CC_NG in https://github.com/cloudfoundry/cloud_controller_ng/issues/939 which was closed in favor of https://github.com/cloudfoundry/cc-api-v3-style-guide/issues/46

No implementation files, entry points, or tests are named. Start by reading the linked cc-api-v3-style-guide issue #46 and the archived cf-swagger project to understand the prior API specification work. Done means CAPI V3 publishes a standard machine-processable API specification suitable for client generation and ecosystem tooling.