Alias for Executing CLI Apps

### What is the problem or limitation you are having?

To execute command line apps I have to write the name of folder that contains my __main__.py as is with underscores

Normally for CLI apps you'd have an enter script or alias to execute the main function.
for example:
```toml
[project.scripts]
markdown-checker = "markdown_checker:main"
```

then you'd execute it using `markdown-checker` not `markdown_checker`

### Describe the solution you'd like

Add alias just like the project.scripts

### Describe alternatives you've considered

I changed the names of everything to not use underscores but it seems that you are detecting this from the folder name and it wouldn't seem right for me to change the folder name to use dashes instead of underscores

### Additional context

_No response_

The issue names no source files or tests. Start by tracing how CLI apps derive their executable name from a package containing __main__.py, then compare that behavior with the [project.scripts] example. Done means a configured dash-separated alias runs the app without requiring the package directory to be renamed.

Written by the indexing model from the issue text.