Add 3D model preview of printer (OpenCentauri#40)

* Add 3D model preview of printer

Embedded F360 interactive embed in machine section- had to change general specs table to vanilla HTML to get side by side with embed.

* Refactor Centauri Carbon Printer specs to Markdown

Updated the layout and formatting of the Centauri Carbon Printer specifications section using Markdown.

Author: robertsamples

docs/machine/index.md

@@ -1,15 +1,20 @@
-Centauri Carbon Printer specifications:
+<div class="grid cards" markdown>
 
-Metric|Value
----|---
-Print area size|256 mm^3
-Hotend|320 °C All-Metal
-Heatbed|110 °C AC-powered
-Max power usage|1100W@220V, 350W@110V
-Weight|17.5kg
-Machine size|398x404x490mm
+-   Centauri Carbon Printer specifications:
+    
+    Metric|Value
+    ---|---
+    Print area size|256 mm^3
+    Hotend|320 °C All-Metal
+    Heatbed|110 °C AC-powered
+    Max power usage|1100W@220V, 350W@110V
+    Weight|17.5kg
+    Machine size|398x404x490mm
+
+-   <iframe src="https://smith150.autodesk360.com/shares/public/SH286ddQT78850c0d8a46fdb9127d46ff4ba?mode=embed" width="800" height="600" allowfullscreen="true" webkitallowfullscreen="true" mozallowfullscreen="true" frameborder="0"></iframe>
+</div>
 
 ![Centauri bottom image](../assets/centauri-bottom.jpg){ width="600" }
 /// caption
 Credit to thijskunst on the OpenCentauri Discord.
-///
+///