Add environment configuration and update main functionality

- Introduced .env.local for environment variables
- Updated .gitignore to include new files
- Enhanced main.py to utilize environment variables for user credentials
- Implemented random sleep delay in API calls and output JSON formatting

.gitignore

@@ -1,2 +1,4 @@
 .env
-.venv/
+.venv/
+accounts.db
+tweets.json