Add an example of writing a tarfile using stdin

[GovernmentPlates]

We currently don't have a (good) example of how to write a tar archive using stdin - we have one for stdout.

Linked PRs

• gh-136858: Adds an example of writing a tarfile using stdin #137510

[AA-Turner]

Another idea discussed with @GovernmentPlates was adding stdin support to python -m tarfile.

A

[aeurielesn]

Created a PR with two new examples and few fixes.