docs: update usage

Author: hyj1991

README.md

@@ -5,3 +5,37 @@
 [![License](https://img.shields.io/github/license/x-profiler/injection)](LICENSE)
 
 An IoC implemention for xprofiler.
+
+## Usage
+
+### Decorator
+
+```ts
+import { Injectable, Inject } from "@xprofiler/injection";
+import { Config } from "./config";
+
+@Injectable()
+export class Foo {
+  @Inject()
+  private config: Config;
+
+  getKmsConfig(@Inject('KMS_KEY') key: string) {
+    return this.config[key];
+  }
+}
+```
+
+### Container
+
+```ts
+import { Container } from "@xprofiler/injection";
+import { Foo, Bar } from "./items";
+
+const container = new Container();
+
+container.set(Foo);
+container.set(Bar);
+
+const foo = container.get(Foo);
+const bar = container.get(Bar);
+```