docs: fix pointer move event parameter for consistency (#584)

Changed event parameter from 'e' to 'event' in onpointermove handler for improved clarity and consistency with instructions.

Author: banu-teja

apps/svelte.dev/content/tutorial/01-svelte/05-events/02-inline-handlers/+assets/app-b/src/lib/App.svelte

@@ -3,9 +3,9 @@
 </script>
 
 <div
-	onpointermove={(e) => {
-		m.x = e.clientX;
-		m.y = e.clientY;
+	onpointermove={(event) => {
+		m.x = event.clientX;
+		m.y = event.clientY;
 	}}
 >
 	The pointer is at {Math.round(m.x)} x {Math.round(m.y)}