[PC-1441] Portenta Max Carrier - Upload or link 3D print case (#1450)

* stl  enclosure link added test

* STL link updated test 2

* ZIP instead of Links test 1

* ZIP instead of Links test 2

* Link to Printables on Essentials

---------

Co-authored-by: Christopher Mendez <mcmchris@hotmail.com>

Author: ArduinoBot

content/hardware/04.pro/carriers/portenta-max-carrier/essentials.md

@@ -2,6 +2,9 @@
     <EssentialElement link="/tutorials/portenta-max-carrier/getting-started" title="Quickstart Guide" type="getting-started">
         A quick guide to installing your board with the Arduino IDE.
     </EssentialElement>
+    <EssentialElement link="https://www.printables.com/model/612174-arduino-max-carrier-enclosure" title="3D Enclosure Files" type="getting-started">
+        Download the 3D files to print your own Portenta Max Carrier enclosure. 
+    </EssentialElement>
 </EssentialsColumn>
 
 <EssentialsColumn title="Suggested Libraries">