Create basic content function

Signed-off-by: Justin Georgi <justin.georgi@gmail.com>

includes/AnnotationContent.php

@@ -0,0 +1,32 @@
+<?php
+namespace MediaWiki\Extension\AnatImageViewer;
+
+use TextContent;
+
+class AnnotationContent extends TextContent {
+
+	public function __construct( $modelId = 'annotation' ) {
+		parent::__construct( $modelId );
+	}
+    
+    /*
+	public function getTextForSearchIndex() {
+	}
+
+	public function getWikitextForTransclusion() {
+	}
+
+	public function getTextForSummary( $maxLength = 250 ) {
+	}
+
+	public function getSize() {
+	}
+
+	public function copy() {
+	}
+    */
+
+	public function isCountable( $hasLinks = null ) {
+        return false;
+	}
+}