add .write method

README.md

@@ -1,7 +1,7 @@
 # An async wrapper for nodejs' `spawn`
 
 ```typescript
-import { simpleSpawn } from "async-spawner";
+import simpleSpawn from "async-spawner";
 await simpleSpawn("ls", ["-al"]);
 ```
 
@@ -12,6 +12,8 @@ let response;
 do{
     response = await ping.waitForNextData();
     console.log("new ping!", response);
+
+    // you can also write to stdin with ping.write("some string")
 }
 ping.kill();
 ```

src/index.ts

@@ -42,6 +42,10 @@ class DeferedSpawn extends Emittery {
     debugger;
     console.log("killed map!");
   }
+
+  write(data: string) {
+    this.process.stdin.write(data);
+  }
 }
 
 export function deferedSpawn(