Docs: improve S3 endpoint-url guidance with note format

Move endpoint-url warning from warning block to note format and
relocate to appropriate section based on code review feedback.
Add reference to AWS service-specific endpoints documentation.

Addresses aws#9479

Refactor the S3 endpoint-url guidance based on review feedback:

- Change from warning block to note format
- Add reference to official AWS service-specific endpoints guide
- Improve clarity of when to use endpoint-url with appropriate actions
- Maintain focus on preventing redirect issues and unintended behavior

This addresses the original issue while incorporating reviewer suggestions
for better placement and formatting of the guidance.

Author: adev-code

awscli/topics/s3-config.rst

@@ -15,11 +15,13 @@ are provided in the case where you need to modify one of these values, either
 for performance reasons or to account for the specific environment where these
 ``aws s3`` commands are being run.
 
-.. warning::
-   S3 commands have a parameter ``--endpoint-url`` that overrides the command's
-   default URL with the given URL. Avoid using the S3 Global Endpoint
-   (``https://s3.amazonaws.com``) as the value for this parameter to prevent redirect
-   issues and other unintended behavior or errors from S3.
+.. note::
+   `S3 high-level commands <https://docs.aws.amazon.com/cli/latest/reference/s3/>`_ provide an option to use a custom endpoint using ``--endpoint-url``.
+   This overrides the default endpoint the command will use.
+   Use caution when configuring this parameter, as it can cause S3 redirect issues and
+   unintended behavior. This parameter is intended for VPC endpoints and other S3 specialized configurations.
+   For more information about endpoint configuration,
+   see `Service-specific endpoints <https://docs.aws.amazon.com/sdkref/latest/guide/feature-ss-endpoints.html>`_.
 
 Configuration Values
 ====================