Add VSCode debugging example(s)

[ptheywood]

Following on from #99, the section on VSCode based gui linux debugging could be expanded with a more detaield description matching the quality of the Visual Studio instructions.

Most of this content can be pulled from our private local gpu box docs.

[Robadob]

Aka this https://github.com/RSE-Sheffield/rses-local-gpus/blob/main/guides/nsight-VSCE/img/readme.md (link is private to people outside rse org)