Add overview and samples to CM similar to Azure.Core

[pallavit]

All the samples similar to - https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/core/Azure.Core/samples/readme.md

[annelo-msft]

@pallavit, is your interest here primarily for end-users of ClientModel-based clients, or for users who are manually authoring clients?

[pallavit]

@KrzysztofCwalina will know more about it, since he asked me to create this work-item :)

[KrzysztofCwalina]

mainly for users of client libraries. We want them to understand that they can change retires (just the number of retries first), that there is a pluggable pipeline, that there are protocol methods, ClientResponse, etc.

[annelo-msft]

For end-user, I would suggest following a structure something like:

• Configuring the client/Configuration
  • Passing credentials
  • Using client options
    • NetworkTimeout
    • Add a custom policy
    • Configuring retries
    • Customizing the transport
      • custom HttpClient
      • proxies
    • Freezing
• Calling client methods
  • Convenience methods/Response
    • Client method return values
      • ClientResult<T>
      • ClientResult<T?>
    • HTTP thru Response
      • Status
      • Headers
      • Content/ContentStream
    • Exception handling
  • Protocol methods
    • How to use
      • Creating BinaryContent input
      • Using ClientResult return value
    • Configuring a request/RequestContext
      • CancellationToken
      • ErrorOptions
      • Headers: add vs. set
      • Add a custom policy
      • Freezing
• Model Reader Writer samples
  • TBD per @m-nash
• Mocking
  • Punt for now?