small typos and update migration timestamp

backend/src/db/migrations/20240222201806_admin-signup-control.ts

@@ -0,0 +1,20 @@
+import { Knex } from "knex";
+
+import { TableName } from "../schemas";
+
+export async function up(knex: Knex): Promise<void> {
+  const isTablePresent = await knex.schema.hasTable(TableName.SuperAdmin);
+  if (isTablePresent) {
+    await knex.schema.alterTable(TableName.SuperAdmin, (t) => {
+      t.string("allowedSignUpDomain");
+    });
+  }
+}
+
+export async function down(knex: Knex): Promise<void> {
+  if (await knex.schema.hasColumn(TableName.SuperAdmin, "allowedSignUpDomain")) {
+    await knex.schema.alterTable(TableName.SuperAdmin, (t) => {
+      t.dropColumn("allowedSignUpDomain");
+    });
+  }
+}