Added help/about box to wysiwyg editor

- To display license info along with shortcuts.
- Extracted out plain layout from 503 error page.
- Added tests to ensure license references are as expected.

tests/HelpTest.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Tests;
+
+class HelpTest extends TestCase
+{
+
+    public function test_wysiwyg_help_shows_tiny_and_tiny_license_link()
+    {
+        $resp = $this->get('/help/wysiwyg');
+        $resp->assertOk();
+        $resp->assertElementExists('a[href="https://www.tiny.cloud/"]');
+        $resp->assertElementExists('a[href="' . url('/libs/tinymce/license.txt') . '"]');
+    }
+
+    public function test_tiny_license_exists_where_expected()
+    {
+        $expectedPath = public_path('/libs/tinymce/license.txt');
+        $this->assertTrue(file_exists($expectedPath));
+
+        $contents = file_get_contents($expectedPath);
+        $this->assertStringContainsString('GNU LESSER GENERAL PUBLIC LICENSE', $contents);
+    }
+
+}