chore(core): update composable jsdocs

packages/core/src/composables/useOnInitHandler.ts

@@ -1,6 +1,11 @@
 import { watch } from 'vue'
 import { useVueFlow } from './useVueFlow'
 
+/**
+ * Composable that handles the initialization of the viewport.
+ *
+ * @internal
+ */
 export function useOnInitHandler() {
   const vfInstance = useVueFlow()