add login validator schema

src/validators/login.validator.ts

@@ -0,0 +1,17 @@
+import { checkSchema } from 'express-validator';
+
+export const validateLogin = checkSchema({
+  email: {
+    notEmpty: {
+      errorMessage: 'Email is required',
+    },
+    isEmail: {
+      errorMessage: 'Invalid email address',
+    },
+  },
+  password: { 
+    notEmpty: {
+      errorMessage: 'Password is required',
+    },
+  },
+});