How to Re-Export Items with pub use in Rust

Re-export items in Rust by adding a `pub use` statement in your library root to expose internal modules at the crate level.

Use pub use in your library crate root (src/lib.rs) to re-export an item from a submodule, making it accessible to users of your crate without them needing to know the internal module path.

mod internal {
    pub fn helper() {}
}

pub use internal::helper;

This allows external code to call my_crate::helper() instead of my_crate::internal::helper().