docs: Update for typescript (#3789)

Co-authored-by: simple <[email protected]>

Author: zereight

docs/react-native.md

@@ -20,7 +20,7 @@ import { onlineManager } from '@tanstack/react-query'
 
 onlineManager.setEventListener(setOnline => {
   return NetInfo.addEventListener(state => {
-    setOnline(state.isConnected)
+    setOnline(!!state.isConnected)
   })
 })
 ```

docs/reference/onlineManager.md

@@ -23,7 +23,7 @@ import { onlineManager } from '@tanstack/react-query'
 
 onlineManager.setEventListener(setOnline => {
   return NetInfo.addEventListener(state => {
-    setOnline(state.isConnected)
+    setOnline(!!state.isConnected)
   })
 })
 ```