Create Notification model

create model for a site notification

backend/src/models/notification.ts

@@ -0,0 +1,51 @@
+import {
+    Entity,
+    Column,
+    PrimaryGeneratedColumn,
+    BaseEntity,
+    CreateDateColumn,
+    UpdateDateColumn
+  } from 'typeorm';
+
+  @Entity()
+  export class Notification extends BaseEntity {
+    @PrimaryGeneratedColumn('uuid')
+    id: string;
+
+    @CreateDateColumn()
+    createdAt: Date;
+
+    @UpdateDateColumn()
+    updatedAt: Date;
+
+    @Column({
+      type: 'timestamp',
+      nullable: true
+    })
+    startDatetime: Date | null;
+
+    @Column({
+        type: 'timestamp',
+        nullable: true
+      })
+      endDatetime: Date | null;
+
+    @Column({
+      nullable: true,
+      type: 'varchar'
+    })
+    maintenanceType: string | null;
+
+    @Column({
+      nullable: true,
+      type: 'varchar'
+    })
+    status: string | null;
+
+    @Column({
+        type: 'timestamp',
+        nullable: true
+      })
+    updatedBy: Date | null;
+
+  }