Update hover-text-and-formatting.md

Author: LiamConnors

Diff for: doc/python/hover-text-and-formatting.md

@@ -285,7 +285,7 @@ fig.show()
 
 ### Specifying the formatting and labeling of custom fields in a Plotly Express figure using a hovertemplate
 
-This example adds custom fields to a Plotly Express figure using the custom_data parameter and then adds a hover template that applies d3 formats to each element of the customdata[n] array and uses HTML to customize the fonts and spacing.
+This example adds custom fields to a Plotly Express figure using the `custom_data` parameter and then adds a hover template that applies d3 formats to each element of the `customdata[n]` array and uses HTML to customize the fonts and spacing.
 
 ```python
 # %%