Merge pull request #13118 from donmccurdy/docs-triangle-containspoint-barycentric

Docs: Add note about barycentric coordinates in triangle.containsPoint() docs

docs/api/math/Triangle.html

@@ -79,7 +79,7 @@
 		<div>
 		[page:Vector3 point] - [page:Vector3] to check.<br /><br />
 
-		Returns true if the passed vector is within the triangle.
+		Returns true if the passed point, when projected onto the plane of the triangle, lies within the triangle.
 		</div>
 
 		<h3>[method:Triangle copy]( [page:Triangle triangle] )</h3>