Fix db relations, add sample data, show categories in frontend menu

software/backend/models/account.model.ts

@@ -0,0 +1,24 @@
+import { Table, Column, Model, HasMany } from 'sequelize-typescript';
+import { Order } from './order.model';
+
+@Table
+export class Account extends Model {
+  @Column
+  username: string
+
+  @Column
+  password: string
+
+  @Column
+  address: string
+
+  @Column
+  firstName: string
+
+  @Column
+  lastName: string
+
+  // Relations
+  @HasMany(() => Order)
+  orders: Order[]
+}