Task scope

• Create platform-specific overview sections for concept modules. Required for flexible deployment feature of CoCo on bare metal.
• Ensure that existing concept files align with OpenShift structure (Overview)
• Ensure that concept modules align with Mod docs reference guide

Changes:

• Each deployment guide contains a new "Overview" assembly for concept modules and the feedback module. This assembly is for general concepts. This change aligns with OCP docs "Overview" structure.
• Each provider section contains a new "Preparation" assembly. (Mod docs guidelines specify noun titles for concept sections.) This assembly contains prerequisites and provider-specific concept modules. This is where concepts such as "flexible deployment mode" for CoCo on bare metal will be placed. (This assembly will be obsolete when we break the deployment guides into platform-specific guides for 1.12.)
• I moved the pull secret closer to the custom peer pod VM image module because it is only required if user selects custom peer pod VM image that is located in a private registry. It looked strange to have it early in the deployment overview.
• I moved the deployment high-level steps to a deployment overview module. This makes the 'deploying' assembly more readable and, I hope, easier to maintain.
• For Azure, I changed "Configuring outbound connections" in header to "Preparing your network" for JTBD framework.
• I moved peer pod customization procedures (initdata, pull secret, custom image) to end of OSC and CC, after 'verification' so that they are preceded by "creating KataConfig CR". (Requested by Emanuele.)