chore: initialize lhbfx project and documentation

backend/scripts/_bootstrap.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+
+def add_src_to_path() -> None:
+    backend_dir = Path(__file__).resolve().parents[1]
+    src_dir = backend_dir / "src"
+    if str(src_dir) not in sys.path:
+        sys.path.insert(0, str(src_dir))