Update sponsors.md

Author: Hubertus Tummescheit

content/events/american2024/sponsors.md

@@ -5,5 +5,6 @@
 |Platinum |<img src="modelon.jpg" width=400> |
 
 | | | | |
-|:-|:-:|:-:|:-:|
-|Gold |<img src="3ds2.jpeg" width=250> |<img src="claytex.jpg" width=300>|<img src="2020_11_04_MKTG_ESI_Logo_ColorTagline_rgb.png" width=300>|
+|:-|:-:|:-:|:-:|:-:|
+|Gold |<img src="claytex.jpg" width=250>|<img src="3ds2.jpeg" width=250>|<img src="2020_11_04_MKTG_ESI_Logo_ColorTagline_rgb.png" width=250>|<img src="juliacomputing.jpg" width=250>|
+|Silver|<img src="maplesoft.jpg" width=250>||||