improved router optional parameter documentation

Author: uguraslan

docs/plugins/router/navigation.md

@@ -98,9 +98,11 @@ This results in: `#player/12/44`
 
 ## Optional router path
 
-You can also specify the optional router path parameter to the Router path.
-This is an advantage as we need not specify two different routes to the same component, instead we can specify optional field in router path with a '?' suffix for the optional params.
+There might be some cases in which you need a route path with an optional parameter at the end. Normally, you would have to define two different routes to the same component, one with the optional parameter and one without. Starting with Lightning-SDK `v5.3.0`, you can specify an optional router path parameter by adding a `?` suffix to the last parameter name.
 
+Please note that only the last parameter of any path is allowed to be an optional parameter. For example, if you have a route path with three parameters, you can make only the last parameter optional, but not the second parameter.
+
+When we define an optional parameter like this:
 ```js
 {
   path: 'player/:assetId/:playlistId?',
@@ -109,26 +111,29 @@ This is an advantage as we need not specify two different routes to the same com
 }
 ```
 
-This will generate two paths as below:
+This will generate two paths internally as below:
 
 ```js
 {
     path: 'player/:assetId/:playlistId'
     component: Player
     name: 'player'
 }
-```
-```js
 {
-    path: 'player/:assetId/',
+    path: 'player/:assetId',
     component: Player,
     name: 'player'
 }
 ```
 
-Note: This will not work if the optional parameter ? is in the middle of the path. For Ex :
+The following example would *not* work because only the last parameter of the path can be optional:
+
 ```js
-    path: 'player/:assetId?/:playlistId'
+{
+  path: 'player/:assetId?/:playlistId',
+  component: Player
+  name: 'player'
+}
 ```