[11.x] Add php doc for ServiceProvider bindings and singletons properties (#52298)

* Add php doc for bindings and singletons magick properties

* Add description

Author: Anton5360

src/Illuminate/Support/ServiceProvider.php

@@ -10,6 +10,10 @@
 use Illuminate\Database\Eloquent\Factory as ModelFactory;
 use Illuminate\View\Compilers\BladeCompiler;
 
+/**
+ * @property array<class-string, class-string> $bindings All of the container bindings that should be registered.
+ * @property array<class-string, class-string> $singletons All of the singletons that should be registered.
+ */
 abstract class ServiceProvider
 {
     /**