- Removed the outdated `atom/README.md` file and replaced it with a new structure for the `atom/` directory to facilitate the incubation of experimental kernel modules.
- Updated `os-structure.md` to include the new `atom/` module for kernel module development and the `utils.rs` file for cross-module utility functions.
- Introduced a new `README.md` in `os/src/atom/` detailing the design principles and directory conventions for experimental modules.
- Created a new `utils.rs` file to house lightweight utility functions that can be reused across multiple modules, establishing criteria for function inclusion.
- Added references to existing functions that meet the criteria for migration into the new `utils.rs`.