docs: Add migration guide

docs/docs/platform-api.md

@@ -1,7 +1,7 @@
 # Platform API
 
 Ts.ED use now, the Platform API to create an application. Platform API give an abstraction layer between your code written with Ts.ED and the [Express.js](https://expressjs.com/fr/) code. 
-It means, a large part of your code isn't coupled with Express itself and can be used with another Platform like [Koa.js](https://koajs.com/) in future (Ts.ED v6).
+It means, a large part of your code isn't coupled with Express.js itself and can be used with another Platform like [Koa.js](https://koajs.com/). 
 
 There are some changes between ServerLoader API (v4/v5) and Platform API (v5.56.0+/v6), to get the original Express Application, Request or Response.
 This page will describe how you can get these instance with the new API. 
@@ -19,7 +19,7 @@ This page will describe how you can get these instance with the new API.
 
 ## Create application
 
-The way to create Ts.ED application, add [middlewares](/docs/middlewares.html), configure Express.Application are impacted by the new Platform API.
+The way to create Ts.ED application, add [middlewares](/docs/middlewares.html), configure Express or Koa are impacted by the new Platform API.
 
 If you use @@ServerLoader@@, you'll probably know this example to create a Ts.ED application:
 
@@ -71,7 +71,10 @@ export const rootDir = __dirname;
 
 @Configuration({
   rootDir,
-  viewsDir: `${rootDir}/views`
+  views: {
+    root: `${rootDir}/views`,
+    viewEngine: 'ejs'
+  }
 })
 export class Server {
   @Constant("viewsDir")
@@ -90,10 +93,6 @@ export class Server {
      .use(bodyParser.urlencoded({
        extended: true
      }));
-
-    // configure express app
-    this.app.raw.set("views", this.viewsDir);
-    this.app.raw.engine("ejs", ejs);
   }
 }
 ```

docs/getting-started/migration-from-v5.md

@@ -9,15 +9,140 @@ meta:
    content: migration getting started ts.ed express typescript node.js javascript decorators mvc class models
 ---
 # Migrate from v5
-
 ## What's news ?
 
+### Platform API
+V6 marks a major evolution of the Ts.ED framework. 
+A lot of work has been done on the internal Ts.ED code since v5 in order to prepare the arrival of this new version. 
+This work was mainly oriented on the creation of an abstraction layer between the Ts.ED framework and Express.js.
+
+ The v5 introduced the [Platform API](/docs/platform-api.md) 
+and the v6 is the confirmation of this API which allows supporting [Express.js](https://expressjs.com/) and [Koa.js](https://koajs.com/) and many more in the future.
+
+We are glad this work resulted in the creation of the [@tsed/platform-express](/https://www.npmjs.com/package/@tsed/platform-express) and 
+[@tsed/platform-koa](/https://www.npmjs.com/package/@tsed/platform-koa).
+
+!!!! ADD new platforms features here (views, statics, multer).
+
+### Schema and OpenSpec
+
+This release finally adds support for [OpenSpec 3](https://swagger.io/docs/specification/about/) while supporting 
+the previous version [Swagger2](https://swagger.io/docs/specification/2-0/basic-structure/). 
+The management of OpenSpec is at the heart of the framework as is [JsonSchema](https://json-schema.org/).
+
+All decorators related to the declaration of schema, routes and endpoints are now integrated in a single module [`@tsed/schema`](https://www.npmjs.com/package/@tsed/schema).
+This module has been designed to be used independently of the Ts.ED framework. 
+You can therefore use it for your projects without installing the whole framework!
+
+New decorators have been added elsewhere to better support JsonSchema and allow the following more complex use cases:
+
+- Managing models using Typescript generics,
+- Management response models by content-type and status code (OAS3).
+
+### JsonMapper
+
+In the same idea, the convertersService code was taken out of the [`@tsed/common`](https://www.npmjs.com/package/@tsed/common) module
+ to the new [`@tsed/json-mapper`](https://www.npmjs.com/package/@tsed/json-mapper) module.
+ It's based on the [`@tsed/schema`](https://www.npmjs.com/package/@tsed/schema) module to perform the mapping of your classes 
+ to a Plain Object JavaScript object and vice versa.
+
+You can therefore use it for your projects without installing the whole framework!
+
 ## Breaking changes
+### Features
+
+- ServerLoader API have been remove in favor of Platform API. See [Platform API](/docs/platform-api.md).
+- Filter feature have been removed in favor of [Pipes](/docs/pipes.md).
+- GlobalErrorHandlerMiddleware have been.removed in favor of [Exception Filters](/docs/exceptions.md#exception-filter).
+
+### Modules
+
+The following modules have been removed:
+
+- `@tsed/testing`: Use @@PlatformTest@@ from `@tsed/common`.
+- `@tsed/multipartfiles`: Use @@MultipartFile@@ from `@tsed/common`.
+- `ts-express-decorators`: Use `@tsed/common`.
+
+### Decorators
+
+The following decorators have been removed:
+
+### @tsed/di
+
+- `@OverrideService`: Use @@OverrideProvider@@
+
+### @tsed/common
+
+- `@ServerSettings`: Use @@Configuration@@.
+- `@ExpressApplication`: Use @@PlatformApplication@@ instead of.
+- `@ExpressRouter`: Use @@PlatformRouter@@ instead of.
+- `@ResponseView`: Use @@View@@ decorator instead of.
+- `@Converter`: @Converter is replaced by @@JsonMapper@@ from `@tsed/json-mapper`. See [Converter to JsonMapper](/getting-started/migration-from-v5.md#converter-to-jsonmapper) section for more details.
+- `@Filter`: Filter feature have been removed.
+- `@MiddlewareError`: Use @@Middleware@@.
+
+#### @tsed/typeorm
+
+- `@EntityRepository`: Use EntityRepository from `typeorm` directly.
 
+#### @tsed/swagger
 
-## GlobalErrorHandler middleware to Exception filter
+Import the following decorators from `@tsed/schema`:
 
-[Exception filter]() is the 
+<ApiList query="['Consumes', 'Deprecated', 'Description', 'Example', 'Name', 'Produces', 'Returns','Security', 'Summary', 'Title'].includes(symbolName)" />
+
+- `@BaseParameter` have been removed.
+- `@Operation` have been removed.
+- `@Responses` have been remove.
+- `@ReturnsArray` have been removed. Use @@Returns@@ from `@tsed/schema`.
+
+## Migration guide
+### ServerLoader to Platform API
+
+All change related to [Platform API](/docs/platform-api.md) and how to migrate the Server on this new API, is described on a dedicated page.
+We encourage you to browse the entire page to migrate from v4/v5 to v6.
+
+See [Platform API documentation](/docs/platform-api.md).
+
+### Inject service in the Server
+
+With @@ServerLoader@@, inject a provider can be done as follows:
+
+```typescript
+import {ServerLoader, ServerSettings} from "@tsed/common";
+import {MyService} from "./services/MyService";
+
+@ServerLoader({
+})
+export class Server extends ServerLoader {
+  $beforeRoutesInit() {
+    const myService = this.injector.get<MyService>(MyService);
+
+    myService.getSomething();
+  }
+}
+```
+
+Now Platform API, the Server class is considered as a @@Provider@@. 
+It means, you can use decorator like @@Constant@@ and @@Inject@@ to get any configuration, provider or service from the DI registry.
+
+```typescript
+import {Configuration} from "@tsed/common"; 
+import {Inject} from "@tsed/di";
+import {MyService} from "./services/MyService";
+
+@Configuration({})
+export class Server {
+  @Inject()
+  myService: MyService;
+
+  $beforeRoutesInit() {
+    this.myService.getSomething();
+  }
+}
+```
+
+### GlobalErrorHandler to Exception Filter
 
 To facilitate your migration, remove the line where you add you custom middleware in the server:
 
@@ -43,4 +168,8 @@ Now you are able to create your own exception filter. Start with the HttpExcepti
 
 <<< @/docs/docs/snippets/exceptions/http-exception-filter.ts
 
-Then try with another error type and finally, remove your custom middleware. 
+Then try with another error type and finally, remove your custom middleware. 
+
+### Converter to JsonMapper
+
+To be redacted