Set ConfigLoader's project directory on module initialization (#4062)

bigquery_etl/__init__.py

@@ -1 +1,8 @@
 """BigQuery ETL."""
+from pathlib import Path
+
+from .config import ConfigLoader
+
+# We need to set the project dir before this module is imported from cli.__init__.py
+if __name__ == "bigquery_etl":
+    ConfigLoader.set_project_dir(Path().absolute())