Add admin reset-password command

Features:
- Add admin reset-password command to reset user passwords
- Support SQLite, PostgreSQL, and MySQL databases
- Use scrypt hashing compatible with CodiMD
- Update README with reset-password usage examples

setup.py

@@ -31,6 +31,9 @@ setup(
             "requests-mock>=1.9.0",
             "pytest-subprocess>=1.5.0",
         ],
+        "admin": [
+            "scrypt>=0.8.0",
+        ],
     },
     entry_points={
         "console_scripts": [