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.

Makefile

@@ -13,7 +13,7 @@ build-snapshot-single: deps test ## Build a snapshot of the application for the
 	@goreleaser build --single-target --snapshot --clean
 
 help: ## Show this help message
-	@echo SteamCache2 Makefile
+	@echo steamcache2 Makefile
 	@echo Available targets:
 	@echo   run                Run the application
 	@echo   run-debug          Run the application with debug logging