Update index.html

Id

Author: Gmac4247

index.html

@@ -123,7 +123,7 @@
 <meta itemprop="isFamilyFriendly" content="true">
 <meta itemprop="typicalAgeRange" content="5-105">
 <meta itemprop="url" content="https://basic-geometry.pages.dev">
-<main itemprop="mainEntity" itemscope itemtype="https://schema.org/LearningResource https://schema.org/MathSolver">
+<main itemprop="mainEntity" itemscope itemtype="https://schema.org/LearningResource https://schema.org/MathSolver" id="cgs">
 <meta itemprop="name" content="Core Geometric System ™">
 <meta itemprop="accessMode" content="mathOnVisual">
 <meta itemprop="accessibilityHazard" content="none">