Docs: Improve & match async-done docs (closes #5)

Author: phated

README.md

@@ -5,17 +5,61 @@ async-settle
 
 Settle your async functions - when you need to know all your parallel functions are complete (success or failure)
 
+Handles completion and errors for callbacks, promises, observables and streams.
+
+Will run call the function on `nextTick`. This will cause all functions to be async.
+
+## Usage
+
+### Successful completion
+
+```js
+var asyncSettle = require('async-settle');
+
+asyncSettle(function(done){
+  // do async things
+  done(null, 2);
+}, function(error, result){
+  // `error` will ALWAYS be null on execution of the first function.
+  // `result` will ALWAYS be a settled object with the result or error of the first function.
+});
+```
+
+### Failed completion
+
+```js
+var asyncSettle = require('async-settle');
+
+asyncSettle(function(done){
+  // do async things
+  done(new Error('Some Error Occurred'));
+}, function(error, result){
+  // `error` will ALWAYS be null on execution of the first function.
+  // `result` will ALWAYS be a settled object with the result or error of the first function.
+});
+```
+
 ## API
 
-### `settle(executor, onComplete)` : Function
+### `asyncSettle(fn, callback)`
+
+Takes a function to execute (`fn`) and a function to call on completion (`callback`).
+
+#### `fn([done])`
+
+Optionally takes a callback to call when async tasks are complete.
+
+Executed in the context of [`async-done`](https://github.com/phated/async-done), with all errors and results being settled.
+
+Completion is handled by [`async-done` completion and error resolution](https://github.com/phated/async-done#completion-and-error-resolution).
 
-Takes a function to execute (`executor`) and a function to call on completion (`onComplete`).
+#### `callback(error, result)`
 
-`executer` is executed in the context of [`async-done`](https://github.com/phated/async-done), with all errors and results being settled.
+Called on completion of `fn` and recieves a settled object as the `result` argument.
 
-`onComplete` will be called with a settled value.
+Teh `error` argument will always be `null`.
 
-#### Settled Values
+#### Settled Object
 
 Settled values have two properties, `state` and `value`.