update readme part 1 of 2

doc/async.md

@@ -2,9 +2,10 @@
 
 > The async processing model is automatically observed by a runtime balancer to prevent any blocking issues, even on page load.
 
-The most methods of each index type provides an async version, e.g.:
+Those methods of each index type provides an async version:
 
 - addAsync()
+- ~~appendAsync()~~
 - updateAsync()
 - removeAsync()
 - searchAsync()
@@ -13,6 +14,8 @@ All those async versions always return a `Promise`, although a callback can be p
 
 When calling async methods of the index, a runtime balancer observe the current event loop and will pass to the next event loop automatically.
 
+### Task Priority
+
 You can control how early the process should move over to the next event loop by passing the option property `priority`:
 
 ```js
@@ -28,6 +31,8 @@ When you have some very smooth running animation you should use a priority of `2
 On Node.js you can slightly increase this priority e.g. to `6`, because here there is no UI involved. 
 A priority value of `9` will cycle the event loop on every ~250ms which is the maximum recommended blocking time. You should not use a value higher than this.
 
+### Polling Tasks
+
 Do not forget to `await` on <u>every</u> async task you apply to the index:
 
 ```js
@@ -36,4 +41,44 @@ for(let i = 0; i < 99999999; i++){
 }
 ```
 
-You can perform queries to the index during any other async batch is running.
+You can perform queries to the index during any other async batch is running.
+
+### Examples
+
+You can assign callbacks to each async function:
+
+```js
+index.addAsync(id, content, function(){
+    console.log("Task Done");
+});
+
+index.searchAsync(query, function(result){
+    console.log("Results: ", result);
+});
+```
+
+Or do not pass a callback function and getting back a `Promise` instead:
+
+```js
+index.addAsync(id, content).then(function(){
+    console.log("Task Done");
+});
+
+index.searchAsync(query).then(function(result){
+    console.log("Results: ", result);
+});
+```
+
+Or use `async` and `await`:
+
+```js
+async function add(){
+    await index.addAsync(id, content);
+    console.log("Task Done");
+}
+
+async function search(){
+    const results = await index.searchAsync(query);
+    console.log("Results: ", result);
+}
+```