chore(): update documentation for triggerImage

Author: jakiestfu

docs/configuration.md

@@ -57,6 +57,13 @@ type KeyboardKey = ModifierKey | (string & {});
 
 ```
 
+- `triggerImage` - The image used for the dev tools trigger
+
+```ts
+{ triggerImage: string }
+
+```
+
 - `urlFlag` - The required flag that must be present in the url to enable devtools.
 
 ```ts