Improve element documentation

Author: TiagoCavalcante

docs/types/element.md

@@ -1,4 +1,5 @@
 It's a 3d element.  
+It may be a [primitive](/mathics-threejs-backend/primitives) or a light.  
 All elements must have a `type` property with its type.
 
 ## Examples

src/lights.js

@@ -14,7 +14,7 @@ import { scaleCoordinate } from './coordinateUtils.js';
 // The 1st parameter is the light object (an element of
 // the lighting array).
 
-// The 2nd parameter is the uniforms buffer, read the comment from
+// The 2nd parameter is the uniforms buffer, read the comments from
 // src/uniforms.js for more information.
 
 // The 3rd parameter is the extent, it is used in e.g. scaleCoordinate.

src/primitives/index.js

@@ -10,7 +10,7 @@
 // The 1st parameter is the primitive object (an element of
 // the elements array).
 
-// The 2nd parameter is the uniforms buffer, read the comment from
+// The 2nd parameter is the uniforms buffer, read the comments from
 // src/uniforms.js for more information.
 
 // The 3rd parameter is the extent, it is used in scaleCoordinate,