added comments

backend/internal/users/password.go

@@ -11,6 +11,7 @@ import (
 	"golang.org/x/crypto/bcrypt"
 )
 
+// ChangePassword handles changing a user's password by decoding a request, validating input, hashing the password, and updating the database.
 func (s Service) ChangePassword(w http.ResponseWriter, r *http.Request) {
 	var err error
 	var req Password