docs: fix response body for local provider (#649)

Co-authored-by: Zoey <zoeykaiser8@gmail.com>

docs/content/1.getting-started/3.quick-start.md

@@ -95,7 +95,7 @@ The backend must accept a request with a body like:
 and return a token that can be used to authenticate future requests in the response body, e.g., like:
 ```ts
 {
-    tokens: {
+    token: {
         accessToken: 'eyBlaBlub'
     }
 }
@@ -142,7 +142,7 @@ The backend must accept a request with a body like:
 and return a token that can be used to authenticate future requests in the response body, e.g., like:
 ```ts
 {
-    tokens: {
+    token: {
         accessToken: 'eyBlaBlub'
         refreshToken: 'eyBlaubwww'
     }