docs: update readme file

Author: WajeehZantout

README.md

@@ -48,7 +48,7 @@ Ignoring the scheduling event, you can see here that we're setting up a function
 
 #### 2. Create your function
 
-This starter kit's Hello World function (which you will of course get rid of) can be found at [`./src/hello.js`](./src/hello.js). There you can see a basic function that's intended to work in conjunction with API Gateway (i.e., it is web-accessible). Like most Serverless functions, the `hello` function accepts an event, context, and callback. When your function is completed, you execute the callback with your response. (This is all basic Serverless; if you've never used it, be sure to read through [their docs](https://serverless.com/framework/docs/).
+This starter kit's Hello World function (which you will of course get rid of) can be found at [`./src/hello.js`](./src/hello.js). There you can see a basic function that's intended to work in conjunction with API Gateway (i.e., it is web-accessible). Like most Serverless functions, the `hello` function is asynchronous and accepts an event & context. (This is all basic Serverless; if you've never used it, be sure to read through [their docs](https://serverless.com/framework/docs/).
 
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