Feat save merge sites (#105)

* refactor: improved new features

* improved new feature

* refactor: merge site save

* bug: mkdir output_dir

---------

Co-authored-by: anna-grim <[email protected]>

Author: anna-grim

src/segmentation_skeleton_metrics/skeleton_metric.py

@@ -139,6 +139,7 @@ def __init__(
         self.load_fragments(fragments_pointer)
 
         # Initialize writers
+        util.mkdir(output_dir, delete=True)
         self.init_writers()
 
     # --- Load Data ---