Add getopts-test demo crate

[Herrtian]

Closes #140.

This adds a small workspace binary that exercises repeated flags, required and optional option values, repeated options, help output, and positional arguments. Its assert_cmd integration tests cover a typical invocation, defaults and --, help, parse errors, and missing positional input.

The path dependency keeps default features disabled so the workspace's existing --no-default-features job continues to test the non-Unicode configuration.

Tests:

• cargo test
• cargo test --no-default-features
• cargo fmt --all -- --check
• RUSTDOCFLAGS=-Dwarnings cargo doc --no-deps
• cargo clippy -p getopts-test --all-targets --no-deps -- -D warnings

[apiraino]

Hi @Herrtian ,

are per our previous warning, you seems to be opening again PRs in quick succession:

• Add getopts-test demo crate #143
• Add examples for required and repeated options #142
• Add rustc-dev-guide reading club links rustc-dev-guide#2919
• Link rust-analyzer setup to editor config files rustc-dev-guide#2918

These PRs were flagged as LLM generated behaviour, so we are placing again a temporary embargo on your GitHub profile, for the last few months we have been receiving an increased amount of automated submissions by users running bots.

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