Docs: consolidate and simply short-term token workflows

Previously, the documentation for the short-term token workflows was
split into three docs, one for each supported cloud. They were also more
complicated than they needed to be. This caused unnecessary burden on
both the maintainers of the repo as well as users attempting to follow
them.

This change combines the three docs into a single workflow. This reduces
the maintenance burden on repo maintainers. It also simplifies the
installation workflows by having the oc extract use the --included and
--install-config flags in addition to outputting the manifests directly
into the installation folder directly

Author: jstuever

README.md

@@ -237,10 +237,7 @@ Cons:
   * Requires an additional cloud infrastructure setup from the user. The [ccoctl](./docs/ccoctl.md) tool can assist in the setup process.
   * Push-button upgrades will not work as the cluster no longer has the admin credentials to mint credentials
 
-Read more about supported clouds by clicking on the links below: 
-  * [AWS](./docs/sts.md)
-  * [Azure](./docs/azure_workload_identity.md)
-  * [GCP](./docs/gcp_workload_identity.md)
+[Documentation](./docs/short-term-credentials.md)
 
 ## Support Matrix
 Cloud | Mint | Mint + Remove Admin Cred | Passthrough | Manual | Token