Fix ex-and import

cli.py

@@ -10,7 +10,7 @@ from models import Instance
 
 
 def load_local_blocklist(filename: str) -> [Instance]:
-    with open(filename, "rb") as f:
+    with open(filename, "r") as f:
         data = toml.load(f)
     instances = []
     for instance_dict in data["instances"]:
@@ -25,7 +25,7 @@ def export_blocklist_toml(blocklist: [Instance], filname: str):
     toml_str = ""
     for instance in blocklist:
         toml_str += f'''
-[instance]
+[[instances]]
 name = "{instance.domain}"
 domain = "{instance.domain}"
 severity = "{instance.severity}"