Update remoteUser info

[bamurtaugh]

To address the outdated reference mentioned here.

Next steps:

• Reach alignment on this PR (placement, wording)
• Merge in same changes for containers.dev - started PR: Update remoteUser info devcontainers.github.io#93
• Update https://aka.ms/dev-containers-non-root to point to new content in containers.dev (easier to traverse as end user rather than diving deep into spec repo itself)

[samruddhikhandale]

Looks good! thanks. ✨

ℹ️ The cpp example in this PR is great and makes a clear point. However, as this PR links to specific lines in the images/templates repo, it is very susceptible to breaking. 🤔

I am good to approve, but maybe we need to be update URLs if cpp image/template updates (which should be rare I think)?

[bamurtaugh]

Thanks for the quick review and great help, @samruddhikhandale!

Makes sense on breakages. Let's go ahead and merge since I agree it's nice to have a concrete example, and we'll just be aware that we'll need to be cautious if there are major changes. An alternative is to just link to the whole file rather than specific lines, but I think it's really helpful to point the user to the specific lines.

[chrmarti]

LGTM, thanks!