Completed add_master pass function

src/database/add.py

@@ -1,8 +1,15 @@
 import mariadb
 
 
-def add_master_pass(hashed_passwd: bytes, salt: bytes, con: mariadb.Connection) -> bool:
-    ...
+def add_master_pass(
+    id: int, hashed_passwd: bytes, salt: bytes, con: mariadb.Connection
+) -> bool:
+    cursor = con.cursor()
+    cursor.execute(
+        "INSERT INTO master_pass (user_id, salt, passwd) VALUES (?, ?, ?)",
+        [id, hashed_passwd, salt],
+    )
+    cursor.close()
 
 
 def add_account(