Add note on using build manglers

Author: richardhj

docs/_guide/your-first-component.md

@@ -33,6 +33,10 @@ By convention Catalyst controllers end in `Element`; Catalyst will omit this whe
 Remember! A class name _must_ include at least two CamelCased words (not including the `Element` suffix). One-word elements will raise exceptions. Example of good names: `UserListElement`, `SubTaskElement`, `PagerContainerElement`
 {% endcapture %}{% include callout.md %}
 
+{% capture callout %}
+When using build tools, some JavaScript minifiers might modify the class name that Catalyst relies on. A best-practice is to allow classnames that end with `Element`. In particular, for Terser, you can use the following config: `{ keep_classnames: /Element$/ }`
+{% endcapture %}{% include callout.md %}
+
 
 ### What does `@controller` do?