documentation: Enhancing documentation on Spring Security integration limitations in DGS Framework

[appreciated]

What are you missing in the docs

The current documentation lacks detailed information about the limitations of the Spring Security integration with the DGS Framework. Specifically, it's not clear where SecurityContextHolder can be appropriately used and where it cannot. This leaves a gap in understanding the full scope of security implementations within the framework.

Some Thoughts which Information should be included in the updated Documentation

I propose to include a section in the documentation that addresses the limitations of the Spring Security integration in the DGS Framework. This section should clarify the contexts in which SecurityContextHolder is applicable and areas where its use is not supported.

Additionally, it would be beneficial to include a direct link to the section on the DGS documentation site that discusses using Spring features like SecurityContextHolder within a CompletableFuture. This can be found at Using Spring Features such as SecurityContextHolder inside a CompletableFuture. This link will guide users to more detailed information on this specific topic, enhancing the overall utility of the documentation.