[Enhancement]: Revise comment at top of examples

[tkhill-AWS]

Background story

The entry point for some people are the examples when they start using Java with AWS.
They appear to go to examples before setting up authentication and/or their environment to use AWS services with Java.

To help mitigate the number of bounces between sites to get things set up, provide users with more information that they need to be ensure they can run the example--authentication and/or general setup.

Replace this (which is currently found at the top of the JavaV2 files):

/**

• Before running this Java V2 code example, set up your development
• environment, including your credentials.
• For more information, see the following documentation topic:
• https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
  */

with this (auth and/or setup links):

Before running this example:

• the SDK must be able to authenticate AWS requests on your behalf. If you have not configured authentication for SDKs and tools,see https://docs.aws.amazon.com/sdkref/latest/guide/access.html in the AWS SDKs and Tools Reference Guide.
• you must have a runtime environment configured with the Java SDK. See https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/setup.html in the Developer Guide if this is not set up.

What does this example accomplish?

NA

Which AWS service(s)?

All.

Which AWS SDKs or tools?

• All languages
• .NET
• C++
• Go (v2)
• Java
• Java (v2)
• JavaScript
• JavaScript (v3)
• Kotlin
• PHP
• Python
• Ruby
• Rust
• Swift
• Not applicable

Are there existing code examples to leverage?

No response

Do you have any reference code?

Scott and I discussed this in our weekly one-on-one.