docs: update README.md

Author: jbl428

README.md

@@ -1 +1,136 @@
 # nest-http-interface
+
+[![npm version](https://badge.fury.io/js/@r2don%2Fnest-http-interface.svg)](https://badge.fury.io/js/@r2don%2Fnest-http-interface)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=r2don_nest-http-interface&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=r2don_nest-http-interface)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=r2don_nest-http-interface&metric=coverage)](https://sonarcloud.io/summary/new_code?id=r2don_nest-http-interface)
+
+This library is inspired by the HTTP interface in Spring 6 and provides a similar API for Nest.js.
+
+## Requirements
+
+- Node.js 18 or later (because this library uses `fetch` internally)
+- Nest.js
+
+## Installation
+
+```bash
+$ npm install @r2don/nest-http-interface
+```
+
+## Usage
+
+First, the module we created must be imported into `AppModule.ts`:
+
+```ts
+import {Module} from '@nestjs/common';
+import {HttpInterfaceModule} from '@r2don/nest-http-interface';
+
+@Module({
+  imports: [HttpInterfaceModule.register()],
+})
+export class AppModule {
+}
+```
+
+Then, you need to create the desired HTTP service and specify several decorators:
+
+```ts
+import {HttpInterface, GetExchange, ResponseBody, imitation} from '@r2don/nest-http-interface';
+
+@HttpInterface()
+class SampleClient {
+  @GetExchange('https://example.com/api') // path or full url
+  @ResponseBody(ResponseTest) // response dto
+  async request(): Promise<ResponseTest> {
+    return imitation(); // this is a mock function to prevent the type error
+  }
+}
+```
+
+After adding the service to the providers in the module, you can use it and make HTTP requests when calling
+the `request` method:
+
+```ts
+import {Module} from '@nestjs/common';
+import {HttpInterfaceModule} from '@your-namespace/http-interface';
+import {SampleClient} from './sample.client';
+
+@Module({
+  imports: [HttpInterfaceModule.register()],
+  providers: [SampleClient]
+})
+export class AppModule {
+}
+```
+
+## Decorators
+
+- `@HttpInterface()`
+
+This decorator is used to mark the class as an HTTP service.
+
+- `@{HTTP Method}Exchange(path: string)`
+
+These decorators are used to mark the method as an HTTP request method.
+`path` is the path or full URL of the request.
+
+- `@ResponseBody(dto: ClassConstructor, options?: ClassTransformOptions)`
+
+This decorator is used to specify the response DTO.
+It requires a class constructor and options from `class-transformer` library.
+
+- `@PathVariable(name?: string)`
+
+This decorator is used to specify the path variable.
+It requires the name of the path variable.
+
+- `@RequestParam(key?: string)`
+
+This decorator is used to specify the query string parameter.
+It requires the key of query string parameter.
+If `key` is not specified, it requires the parameter to be an object.
+
+```ts
+// with key
+class TestService {
+  request(@RequestParam('foo') query: string): string {
+    return imitation();
+  }
+}
+
+// without key
+class TestService {
+  request(@RequestParam() query: { foo: string }): string {
+    return imitation();
+  }
+}
+```
+
+- `@RequestHeader(key?: string)`
+
+This decorator is used to specify the request header.
+It requires the key of request header optionally.
+
+- `@RequestBody(key?: string)`
+
+This decorator is used to specify the request body.
+`application/json` is used as the content type.
+It requires the key of request body optionally.
+
+- `@RequestForm(key?: string)`
+
+This decorator is used to specify the request form.
+`application/x-www-form-urlencoded` is used as the content type.
+It requires the key of request body optionally.
+
+## License
+
+This library is licensed under the MIT license.
+
+## Testing
+
+To run tests, execute:
+
+```bash
+$ pnpm test
+```