Refactor module naming and update references to steamcache2

- Changed module name from `s1d3sw1ped/SteamCache2` to `s1d3sw1ped/steamcache2` for consistency.
- Updated all import paths and references throughout the codebase to reflect the new module name.
- Adjusted README and Makefile to use the updated module name, ensuring clarity in usage instructions.

README.md

@@ -21,7 +21,7 @@ SteamCache2 is a blazing fast download cache for Steam, designed to reduce bandw
 1. **Clone and build:**
    ```bash
    git clone <repository-url>
-   cd SteamCache2
+   cd steamcache2
    make  # This will run tests and build the application
    ```