doc: clarify trigger loading strategy

Fixes #489

Author: harlan-zw

docs/content/docs/1.guides/1.script-triggers.md

@@ -45,7 +45,7 @@ export default defineNuxtConfig({
   scripts: {
     globals: {
       myScript: ['https://example.com/script.js', {
-        // load however you like!
+        // load after page is fully interactive (idle loading)
         trigger: 'onNuxtReady'
       }]
     }
@@ -57,7 +57,37 @@ export default defineNuxtConfig({
 
 ## Default Behavior
 
-By default, scripts are loaded when Nuxt is fully hydrated. You can change this default by modifying the [defaultScriptOptions](/docs/api/nuxt-config#defaultscriptoptions).
+By default, scripts are loaded when Nuxt is fully hydrated using the `onNuxtReady` trigger. This provides an "idle loading" behavior where scripts load only after the page is fully interactive, minimizing impact on Core Web Vitals and user experience.
+
+The `onNuxtReady` trigger ensures scripts load:
+- After Nuxt hydration is complete
+- When the browser is idle and the main thread is available
+- Without blocking critical page rendering or user interactions
+
+This is more effective than using `defer` or `fetchpriority="low"` attributes alone, as it waits for the application to be fully ready rather than just the HTML parsing to complete.
+
+You can change this default by modifying the [defaultScriptOptions](/docs/api/nuxt-config#defaultscriptoptions).
+
+## Idle Loading with onNuxtReady
+
+The `onNuxtReady` trigger is perfect for non-critical scripts like chat widgets, analytics, or marketing tools that should load with minimal performance impact:
+
+```ts
+// Chat widget - loads after page is fully interactive
+useScript('https://widget.intercom.io/widget/abc123', {
+  trigger: 'onNuxtReady' // default behavior
+})
+
+// Explicitly using onNuxtReady for clarity
+useScriptGoogleAnalytics({
+  id: 'GA_MEASUREMENT_ID',
+  scriptOptions: {
+    trigger: 'onNuxtReady'
+  }
+})
+```
+
+This approach ensures your Core Web Vitals remain optimal while still loading necessary third-party scripts.
 
 ## Element Event Triggers