fix emoji

Author: carriewright11

modules/Data_Visualization/Data_Visualization.Rmd

@@ -780,7 +780,7 @@ food_bar +
 
 ## Tip - Check what you plot {.codesmall}
 
-:warning: May not be plotting what you think you are! :warning:
+⚠️ May not be plotting what you think you are! ⚠️
 
 ```{r, fig.width=5 , fig.height=3, fig.align='center'}
 ggplot(food, aes(x = item_ID,