Fix destination copy on Python script

build_site.py

 import shutil
 import os
+if os.path.exists("public"):
+    shutil.rmtree("public")
 os.mkdir("public")
 shutil.copyfile("templates/index.html", "public/index.html")
-shutil.copy("static/*", "public/")
+shutil.copytree("static", "public/", dirs_exist_ok=True)