Added foundational modules for core functionalities:

- Introduced `walk.rs` as a parallel directory walker for search operations.
- Implemented basic index handling in `commands/index.rs`.
- Created `utils/config.rs` for configuration management with placeholders for future enhancements.

src/filetypes.rs

@@ -0,0 +1,43 @@
+// use crate::dir_entry;
+// use crate::filesystem;
+// 
+// use faccess::PathExt;
+// 
+// /// Whether or not to show
+// #[derive(Default)]
+// pub struct FileTypes {
+//     pub files: bool,
+//     pub directories: bool,
+//     pub symlinks: bool,
+//     pub block_devices: bool,
+//     pub char_devices: bool,
+//     pub sockets: bool,
+//     pub pipes: bool,
+//     pub executables_only: bool,
+//     pub empty_only: bool,
+// }
+// 
+// impl FileTypes {
+//     pub fn should_ignore(&self, entry: &dir_entry::DirEntry) -> bool {
+//         if let Some(ref entry_type) = entry.file_type() {
+//             (!self.files && entry_type.is_file())
+//                 || (!self.directories && entry_type.is_dir())
+//                 || (!self.symlinks && entry_type.is_symlink())
+//                 || (!self.block_devices && filesystem::is_block_device(*entry_type))
+//                 || (!self.char_devices && filesystem::is_char_device(*entry_type))
+//                 || (!self.sockets && filesystem::is_socket(*entry_type))
+//                 || (!self.pipes && filesystem::is_pipe(*entry_type))
+//                 || (self.executables_only && !entry.path().executable())
+//                 || (self.empty_only && !filesystem::is_empty(entry))
+//                 || !(entry_type.is_file()
+//                 || entry_type.is_dir()
+//                 || entry_type.is_symlink()
+//                 || filesystem::is_block_device(*entry_type)
+//                 || filesystem::is_char_device(*entry_type)
+//                 || filesystem::is_socket(*entry_type)
+//                 || filesystem::is_pipe(*entry_type))
+//         } else {
+//             true
+//         }
+//     }
+// }