chore(credit): [import] add author and link to the process manager

Author: maxperei

src/ProcessManager/ProcessManager.php

@@ -9,6 +9,10 @@
 
 /**
  * The process manager for executing multiple processes in parallel.
+ *
+ * @thanks BluePsyduck <bluepsyduck@gmx.com>
+ *
+ * @see https://github.com/BluePsyduck/symfony-process-manager
  */
 class ProcessManager implements ProcessManagerInterface
 {

src/ProcessManager/ProcessManagerInterface.php

@@ -8,6 +8,10 @@
 
 /**
  * The interface of the process manager.
+ *
+ * @thanks BluePsyduck <bluepsyduck@gmx.com>
+ *
+ * @see https://github.com/BluePsyduck/symfony-process-manager
  */
 interface ProcessManagerInterface
 {