Release of v5.1.1-alpha1

Move all banners to GitHub. Adds library phpspreadsheet to JCB. Adds import item example to demo component. Updates the Superpower class with the GetRemote class in the plugin. Ensures the super power autoloader triggers the correct repositories.

libraries/phpspreadsheet/vendor/maennchen/zipstream-php/test/Zs/ExtendedInformationExtraFieldTest.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ZipStream\Test\Zs;
+
+use PHPUnit\Framework\TestCase;
+use ZipStream\Zs\ExtendedInformationExtraField;
+
+class ExtendedInformationExtraFieldTest extends TestCase
+{
+    public function testSerializesCorrectly(): void
+    {
+        $extraField = ExtendedInformationExtraField::generate();
+
+        $this->assertSame(
+            bin2hex((string) $extraField),
+            '5356' . // 2 bytes; Tag for this "extra" block type
+            '0000' // 2 bytes; TODO: Document
+        );
+    }
+}