feat(docs): add scene support

README.md

@@ -1,4 +1,5 @@
 # NestJS VK
+
 [![npm](https://img.shields.io/npm/v/nestjs-vk.svg?style=flat-square)](https://www.npmjs.com/package/nestjs-vk)
 [![NPM](https://img.shields.io/npm/dt/nestjs-vk.svg?style=flat-square)](https://www.npmjs.com/package/nestjs-vk)
 [![GitHub last commit](https://img.shields.io/github/last-commit/xtcry/nestjs-vk)](https://github.com/xtcry/nestjs-vk)
@@ -15,7 +16,7 @@ This module provides a quick and easy way to interact with the VK API and create
 
 - Simple. Easy to use.
 - Ability to create custom decorators.
-- ~~Scenes support.~~
+- Scenes support.
 - Ability to run multiple bots simultaneously.
 - Full support of NestJS guards, interceptors, filters and pipes!
 
@@ -26,11 +27,16 @@ $ npm i nestjs-vk vk-io
 ```
 
 ## Usage
+
 Once the installation process is complete, we can import the `VkModule` into the root `AppModule`:
+
 ```typescript
 import { Module } from '@nestjs/common';
 import { VkModule } from 'nestjs-vk';
 
+import { AppUpdate } from './app.update';
+import { SimpleScene } from './scene/simple.scene';
+
 @Module({
   imports: [
     VkModule.forRoot({
@@ -39,17 +45,21 @@ import { VkModule } from 'nestjs-vk';
         pollingGroupId: +process.env.VK_BOT_GROUP_ID,
         apiMode: 'sequential',
       },
-    })
+    }),
   ],
+  providers: [AppUpdate, SimpleScene],
 })
 export class AppModule {}
 ```
 
 Then create `app.update.ts` file and add some decorators for handling VK bot API updates:
+
 ```typescript
 import { InjectVkApi, Update, Ctx, Message, Hears, HearFallback } from 'nestjs-vk';
 import { MessageContext, VK } from 'vk-io';
+
 import { AppService } from './app.service';
+import { SIMPLE_SCENE } from './vk.constants';
 
 @Update()
 export class AppUpdate {
@@ -80,6 +90,12 @@ export class AppUpdate {
     return 'Hey there';
   }
 
+  @Hears(/scene( ?(?<state>[0-9]+))?$/i)
+  async hearsScene(@Ctx() ctx: MessageContext) {
+    const stateNumber = ((e) => (isNaN(Number(e)) ? null : Number(e)))(ctx.$match?.groups?.state);
+    ctx.scene.enter(SIMPLE_SCENE, { state: { stateNumber } });
+  }
+
   @Hears(['/sub', 'subscriber'])
   async onSubscriberCommand(@Ctx() ctx: MessageContext) {
     const isSib = await this.vk.api.groups.isMember({
@@ -102,3 +118,60 @@ export class AppUpdate {
   }
 }
 ```
+
+For a simple scene, let's create an `app.update.ts` file and do a few steps for it:
+
+```typescript
+import { Scene, AddStep, Ctx, SceneEnter, SceneLeave } from 'nestjs-vk';
+import { MessageContext } from 'vk-io';
+import { IStepContext } from '@vk-io/scenes';
+
+import { SIMPLE_SCENE } from './vk.constants';
+
+@Scene(SIMPLE_SCENE)
+export class SimpleScene {
+  @SceneEnter()
+  async onSceneEnter(@Ctx() ctx: IStepContext) {
+    const { stateNumber } = ctx.scene.state;
+    await ctx.reply(
+      `Hello! I am a simple scene. Your state number is ${stateNumber}.\n` +
+        ` You can send me a number and I will multiply it by 2.`,
+    );
+  }
+
+  @SceneLeave()
+  async onSceneLeave(@Ctx() ctx: IStepContext) {
+    await ctx.reply('Bye!');
+  }
+
+  // @Hears('exit')
+  // async onHearsExit(@Ctx() ctx: IStepContext) {
+  //   await ctx.scene.leave();
+  // }
+
+  @AddStep()
+  async onAddStep(@Ctx() ctx: IStepContext) {
+    let { stateNumber: number } = ctx.scene.state;
+
+    if (!ctx.scene.step.firstTime) {
+      number = Number(ctx.text);
+    }
+
+    if (ctx.scene.step.firstTime && number === null) {
+      await ctx.reply('Please send me a number.');
+      return;
+    }
+
+    if (isNaN(number)) {
+      await ctx.reply('Wrong. Please send me a number.');
+      return;
+    }
+
+    await ctx.reply(`Your number multiplied by 2 is ${number * 2}.`);
+
+    if (number > 20 && number % 2 === 0) {
+      await ctx.scene.leave();
+    }
+  }
+}
+```