0.2.2: Command checks fail due to color output and trying to check non-test files

Hi again 👋

After disabling the tests mentioned in #140 I was unfortunately met with further failing tests.

The below is a short excerpt, please have a look a the attached full logs for build and check for details.

```
Running tests/command_check.rs (target/debug/deps/command_check-d1f8a22b4302851f)

running 8 tests
test check_stdin_with_file ... FAILED
test check_stdin ... FAILED
test check_empty_stdin_with_file ... FAILED
test check_exclusion ... ok
test check_quiet_with_config ... FAILED
test check_empty_stdin ... FAILED
test check ... FAILED
test check_quiet ... FAILED
```

[mado-0.2.2-1-x86_64-build.log](https://github.com/user-attachments/files/19411308/mado-0.2.2-1-x86_64-build.log)
[mado-0.2.2-1-x86_64-check.log](https://github.com/user-attachments/files/19411309/mado-0.2.2-1-x86_64-check.log)

From the logs I gather that some of the tests are somehow picking up the markdown files of dependencies in the target directory somewhere.
I don't think this is intentional and I guess the tests should instead specifically only target test files.

In other tests it appears as if the output is cross-checked but it looks like it fails on colored vs. plain output!

As further information (also for #140), this is how I'm building this project:

```shell
export RUSTUP_TOOLCHAIN=stable
export CARGO_TARGET_DIR=target
cargo fetch --locked --target "$(rustc -vV | sed -n 's/host: //p')"
cargo build --frozen --release --all-features
cargo test --frozen --all-features
```