update docs

docs/20_Usage.md

@@ -9,7 +9,7 @@ require_once('../classes/tinyrouter.class.php');
 
 ### Config
 
-Define the routes as array elements.
+Define the routes and its return values as array elements.
 First item is a route. The 2nd item is something you get back as callback item of a matching route. Here are strings but you can define other variable types like objects here.
 
 ```php
@@ -23,8 +23,9 @@ $aRoutes=[
     [ "/apps/@appid:[0-9a-f]*/@what:[a-z]*", "acess_appdata"  ],
 //    ^                                       ^
 //    |                                       |
-//    route                                   callback (string|array|... any type you want to get back)
-//      string     = folder
+//    |                                       callback
+//    route                                   a string|array|...
+//      string     = folder                   any type you want to get back
 //      @var       = set a variable
 //      @var:regex = set variable if it matches the given regex
 ];
@@ -62,9 +63,9 @@ The getRoute() method returns an array
 
 * request url
 * request method (GET|POST|PUT|DELETE|...)
-* with the matching route
-* name of the callback
-* vars on parts with starting @ chars
+* the detected best matching route
+* name of the callback (read from 2nd value in your config)
+* vars contains all variables coming from url parts starting with a @ char
 
 ```txt
 // on url /apps/12345/meta
@@ -86,12 +87,12 @@ Array
 
 If no route matches - or a variable did not match a required regex - then getRoute() returns *false*.
 
-### Other getters
+### Specific getters
 
-Maybe the keys of the array change in future. You can access the data with specialized getter functions:
+Maybe the keys of the array above change in future. You can access the data with specialized getter functions:
 
 ```php
-// get the fallback 
+// get the callback item only
 $sAction=$oRouter->getCallback();
 
 // all vars
@@ -102,7 +103,7 @@ $sAppId=$oRouter->getVar('appid');
 $sWhat=$oRouter->getVar('what');
 ```
 
-You can get the nth element from the request url. In our example with index 0 you 
+You can get the nth element from the request url. In our example with index 0 you
 get the 1st element which can be "config" or "apps".
 
 ```php
@@ -121,4 +122,7 @@ To continue with the variables above: you maybe want to execute the method with
 
 ```php
 $aData=$Obj->$sAction($sAppId, $sWhat);
+// ...
+header('Content-Type: application/json');
+echo json_encode($aData);
 ```