Added transclusion tests and fixed other tests

tests/Entity/PageContentTest.php

@@ -0,0 +1,33 @@
+<?php
+
+class PageContentTest extends TestCase
+{
+
+    public function test_page_includes()
+    {
+        $page = \BookStack\Page::first();
+        $secondPage = \BookStack\Page::all()->get(2);
+
+        $secondPage->html = "<p id='section1'>Hello, This is a test</p><p id='section2'>This is a second block of content</p>";
+        $secondPage->save();
+
+        $this->asAdmin()->visit($page->getUrl())
+            ->dontSee('Hello, This is a test');
+
+        $originalHtml = $page->html;
+        $page->html .= "{{@{$secondPage->id}}}";
+        $page->save();
+
+        $this->asAdmin()->visit($page->getUrl())
+            ->see('Hello, This is a test')
+            ->see('This is a second block of content');
+
+        $page->html = $originalHtml . " Well {{@{$secondPage->id}#section2}}";
+        $page->save();
+
+        $this->asAdmin()->visit($page->getUrl())
+            ->dontSee('Hello, This is a test')
+            ->see('Well This is a second block of content');
+    }
+
+}