add black background color to figure (#154)

Author: andrew-bean

sponsors.qmd

@@ -2,6 +2,6 @@
   title: "Sponsors"
 ---
 
-::: {.px-3 .py-5 .my-1 .text-center}
-[![Bay Area Biotech-Pharma Statistics Workshop (BBSW)](media/bbswLogoDarkBg.png)](https://www.bbsw.org/)
+::: {.px-3 .py-5 .my-1 .text-center }
+[![Bay Area Biotech-Pharma Statistics Workshop (BBSW)](media/bbswLogoDarkBg.png){style="background-color: black;"}](https://www.bbsw.org/)
 :::