docs: finish blocker doc

docs/api/hooks/useBlocker.md

@@ -15,7 +15,7 @@ Allow the application to block navigations within the SPA and present the user a
 ## Signature
 
 ```tsx
-useBlocker(shouldBlock): Blocker
+useBlocker(shouldBlock: boolean | BlockerFunction): Blocker
 ```
 
 ## Params
@@ -24,7 +24,43 @@ useBlocker(shouldBlock): Blocker
 
 [modes: framework, data]
 
-_No documentation_
+**boolean**
+
+Whether or not the navigation should be blocked. If `true`, the blocker will prevent the navigation. If `false`, the blocker will not prevent the navigation.
+
+[**BlockerFunction**](https://api.reactrouter.com/v7/types/react_router.BlockerFunction.html)
+
+A function that returns a boolean indicating whether the navigation should be blocked.
+
+```tsx
+const blocker = useBlocker(
+  ({ currentLocation, nextLocation, historyAction }) =>
+    value !== "" &&
+    currentLocation.pathname !== nextLocation.pathname
+);
+```
+
+## Blocker
+
+The [Blocker](https://api.reactrouter.com/v7/types/react_router.Blocker.html) object returned by the hook. It has the following properties:
+
+### `state`
+
+- `unblocked` - the blocker is idle and has not prevented any navigation
+- `blocked` - the blocker has prevented a navigation
+- `proceeding` - the blocker is proceeding through from a blocked navigation
+
+### `location`
+
+When in a `blocked` state, this represents the location to which we blocked a navigation. When in a `proceeding` state, this is the location being navigated to after a `blocker.proceed()` call.
+
+### `proceed()`
+
+When in a `blocked` state, you may call `blocker.proceed()` to proceed to the blocked location.
+
+### `reset()`
+
+When in a `blocked` state, you may call `blocker.reset()` to return the blocker back to an `unblocked` state and leave the user at the current location.
 
 ## Examples