feat : add setup_logging with hierarchical astrai logger

- setup_logging(): attach handler only to astrai logger, not root
- all astrai.* sub-module loggers inherit automatically
- controlled by ASTR_LOG_LEVEL env var (default INFO)
- called in if __name__ == '__main__' of each CLI script

scripts/tools/benchmark.py

@@ -1,6 +1,7 @@
 import click
 import torch
 
+from astrai import setup_logging
 from astrai.config import AutoRegressiveLMConfig
 
 _DTYPES = ["bfloat16", "float16", "float32"]
@@ -204,4 +205,5 @@ def benchmark_command(
 
 
 if __name__ == "__main__":
+    setup_logging()
     benchmark_command()