docs: prep for tanstack.com migration to TSR (#663)

Author: tannerlinsley

docs/config.json

@@ -188,6 +188,10 @@
             {
               "label": "FormApi",
               "to": "framework/react/reference/formApi"
+            },
+            {
+              "label": "FieldApi",
+              "to": "framework/react/reference/fieldApi"
             }
           ]
         },

docs/framework/react/reference/fieldApi.md

@@ -5,7 +5,7 @@ title: Field API
 
 ### `FieldApi<TParentData, TName, TFieldValidator, TFormValidator, TData>`
 
-When using `@tanstack/react-form`, the [core field API](../../reference/fieldApi) is extended at type level with additional methods for React-specific functionality:
+When using `@tanstack/react-form`, the [core field API](../../../../reference/fieldApi) is extended at type level with additional methods for React-specific functionality:
 
 - ```tsx
   Field: FieldComponent<TParentData, TFormValidator>

docs/framework/react/reference/formApi.md

@@ -5,7 +5,7 @@ title: Form API
 
 ### `FormApi<TFormData, TFormValidator>`
 
-When using `@tanstack/react-form`, the [core form API](../../reference/formApi) is extended at type level with additional methods for React-specific functionality:
+When using `@tanstack/react-form`, the [core form API](../../../../reference/formApi) is extended at type level with additional methods for React-specific functionality:
 
 - ```tsx
   Field: FieldComponent<TFormData, TFormValidator>