LuauRequireMode is pub(crate) instead of pub, breaking programmatic usage of BundleRequireMode::Luau

[amirfarzamnia]

Describe the bug
When using darklua_core programmatically, LuauRequireMode cannot be instantiated directly because it is marked as pub(crate) in the module hierarchy, whereas PathRequireMode is exported as pub.

As a result, users cannot construct a BundleConfiguration using BundleRequireMode::Luau in Rust code.

To Reproduce
Attempting to construct a bundle configuration using BundleRequireMode::Luau:

use darklua_core::rules::require::LuauRequireMode; // Error: module or type is private / pub(crate)
use darklua_core::rules::BundleRequireMode;
use darklua_core::config::Configuration;
use darklua_core::bundle::BundleConfiguration;

let configuration = Configuration::empty().with_bundle_configuration(
    BundleConfiguration::new(
        BundleRequireMode::Luau(LuauRequireMode::default()),
    )
);

Expected behavior
LuauRequireMode should be publicly accessible (pub) just like PathRequireMode, allowing full programmatic access:

use darklua_core::rules::require::PathRequireMode; // Works fine

let configuration = Configuration::empty().with_bundle_configuration(
    BundleConfiguration::new(
        BundleRequireMode::Path(PathRequireMode::default()),
    )
);

Suggested Solution
Change the visibility of LuauRequireMode from pub(crate) to pub.