update docs

docs/content/1.get-started/3.tips/5.headers.md

@@ -4,7 +4,7 @@ title: Headers
 
 # Headers
 
-We can use the built-in `useRequestHeaders` to access/pass headers to any future internal requests during SSR.
+We can use the built-in `useRequestHeaders` to set outgoing request headers:
 
 ```ts [plugins/client.ts]
 export default defineNuxtPlugin(() => {
@@ -13,8 +13,12 @@ export default defineNuxtPlugin(() => {
   const client = createTRPCProxyClient<AppRouter>({
     links: [
       httpBatchLink({
+        // headers need to be a function so it gets called dynamically
+        // every HTTP request
         headers() {
-          return headers
+          return {
+            ...headers
+          }
         }
       }),
     ],