docs: add pr link

Author: rudyxu

active-rfcs/0000-infer-attrs.md

@@ -1,7 +1,7 @@
 - Start Date: 2023-01-01
 - Target Major Version: 3.x
 - Reference Issues: [vuejs/core#3452](https://github.com/vuejs/core/issues/3452), [vuejs/core#5423](https://github.com/vuejs/core/issues/5423), 
-- Implementation PR: [vuejs/core#]()
+- Implementation PR: [vuejs/core#7444](https://github.com/vuejs/core/pull/7444)
 
 # Summary
 
@@ -70,7 +70,7 @@ The following blow is the design details.
 - `attrs` is lower priority  than `props`.
 
 
-## `useAttrs`
+## `useAttrs<T>`
 In the `setup-script`, the generic type of `useAttrs` will compile to the second param of `defineComponent`