Documentation, improvements on validation, refactor

Validate get boad
change pattern of api params
Import only one board by api
Populate data from api
Update class diagram
Update documentation
Add return when success
Sort comments
Fix order of cards
Instructions of attachments

Signed-off-by: Vitor Mattos <vitor@php.rio>

lib/Service/ABoardImportService.php

@@ -37,6 +37,7 @@ abstract class ABoardImportService {
 	public static $name = '';
 	/** @var BoardImportService */
 	private $boardImportService;
+	/** @var bool */
 	protected $needValidateData = true;
 	/** @var Stack[] */
 	protected $stacks = [];