Added PHP API reference links

Author: mnocon

docs/api/php_api/php_api.md

@@ -67,11 +67,11 @@ Value objects come with their own properties, such as `$content->id` or `$locati
 ### Creating and updating objects
 
 Value objects fetch data from the repository and are read-only.
-To create and modify repository values, use data structures, such as [`ContentService::newContentCreateStruct()`](https://github.com/ibexa/core/blob/v4.6.6/src/contracts/Repository/ContentService.php#L572) or [`LocationService::newLocationUpdateStruct()`](https://github.com/ibexa/core/blob/v4.6.6/src/contracts/Repository/LocationService.php#L238).
+To create and modify repository values, use data structures, such as [`ContentService::newContentCreateStruct()`](/api/php_api/php_api_reference/classes/Ibexa-Contracts-Core-Repository-ContentService.html#method_newContentCreateStruct) or [`LocationService::newLocationUpdateStruct()`](/api/php_api/php_api_reference/classes/Ibexa-Contracts-Core-Repository-LocationService.html#method_newLocationCreateStruct).
 
 ### Value info objects
 
-Some complex value objects have an `Info` counterpart, for example [`ContentInfo`](https://github.com/ibexa/core/blob/4.6/src/contracts/Repository/Values/Content/ContentInfo.php) for [`Content`](https://github.com/ibexa/core/blob/4.6/src/contracts/Repository/Values/Content/Content.php).
+Some complex value objects have an `Info` counterpart, for example [`ContentInfo`](/api/php_api/php_api_reference/classes/Ibexa-Contracts-Core-Repository-Values-Content-ContentInfo.html) for [`Content`](/api/php_api/php_api_reference/classes/Ibexa-Contracts-Core-Repository-Values-Content-Content.html).
 These objects provide you with lower-level information.
 For instance, `ContentInfo` contains `currentVersionNo` or `remoteId`, while `Content` enables you to retrieve fields, content type, or previous versions.