Fix 6771d3c5932a8b8080434cdbdd04817b9f4db88f

Apply nameservers env to gateway connection

Slight reorganization in app.py and config.py, add nameservers env

Fix bug involving nonexistent users, remove unnecessary identifier conversions

Refactor to use user IDs for checking instead of usernames, fix notification duplication bug by storing processed_ids instead of newest_id, add load handling to AiohttpManager

Add mention flag, fix inconsistencies in some output messages

Fix output logic in check_notifs_loop and addrule and removerule argument handling

Add README for HF Space config, move repo README to .github

Handle API and server errors more gracefully, improve maintainability of codebase, bug fixes