Add a comment about password hashing in adduser

adduser

@@ -21,6 +21,7 @@ def adduser(username, firstname, lastname, email, password):
     else:
         fullname = f'{firstname} {lastname}'
 
+    # Generate password hash using OpenSSL
     with open('password', 'w') as f:
         f.write(password)
     hashed_password = check_output(['openssl', 'passwd', '-6', '-in', 'password']).decode('utf-8')[:-1]