feat(Docs) Track referrers to Kapa AI on homepage (#14940)

Author: sergical

src/components/askAiSearchParams.tsx

@@ -3,8 +3,11 @@
 import {Fragment, useEffect} from 'react';
 import {useSearchParams} from 'next/navigation';
 
+import {usePlausibleEvent} from 'sentry-docs/hooks/usePlausibleEvent';
+
 export default function AskAiSearchParams() {
   const searchParams = useSearchParams();
+  const {emit} = usePlausibleEvent();
 
   useEffect(() => {
     const askAi = searchParams?.get('askAI');
@@ -13,11 +16,16 @@ export default function AskAiSearchParams() {
       if (window.Kapa?.open && askAi === 'true') {
         // open kapa modal
         window.Kapa.open({});
+        if (searchParams?.get('referrer')) {
+          emit('Ask AI Referrer', {
+            props: {referrer: searchParams.get('referrer') ?? ''},
+          });
+        }
       }
     }, 300);
 
     return () => clearTimeout(timer);
-  }, [searchParams]);
+  }, [searchParams, emit]);
 
   return <Fragment />;
 }

src/hooks/usePlausibleEvent.tsx

@@ -4,6 +4,9 @@ import {ReadProgressMilestone} from 'sentry-docs/types/plausible';
 
 // Adding custom events here will make them available via the hook
 type PlausibleEventProps = {
+  ['Ask AI Referrer']: {
+    referrer: string;
+  };
   ['Copy Expandable Content']: {
     page: string;
     title: string;