Update website-listings-custom.qmd (#1159)

Fix what appears to be a typo (the example that follows uses `templateParams`instead of `params`).

Author: andrewpbray

docs/websites/website-listings-custom.qmd

@@ -216,7 +216,7 @@ listing:
     param1: "param-value"
 ```
 
-Template parameters can then be accessed in your template using `<%= params.param1 %>`. For example, we can modify the above `custom.ejs` template as follows:
+Template parameters can then be accessed in your template using `<%= templateParams.param1 %>`. For example, we can modify the above `custom.ejs` template as follows:
 
 ``` html
 <h3><%= templateParams.param1 %></h3>