added some search params documentation

Author: ryanflorence

docs/api/hooks/useSearchParams.md

@@ -33,4 +33,65 @@ useSearchParams(defaultInit): undefined
 
 [modes: framework, data, declarative]
 
-_No documentation_
+You can initialize the search params with a default value, though it **will not** change the URL on the first render.
+
+```tsx
+// a search param string
+useSearchParams("?tab=1");
+
+// a short-hand object
+useSearchParams({ tab: "1" });
+
+// object keys can be arrays for multiple values on the key
+useSearchParams({ brand: ["nike", "reebok"] });
+
+// an array of tuples
+useSearchParams([["tab", "1"]]);
+
+// a URLSearchParams object
+useSearchParams(new URLSearchParams("?tab=1"));
+```
+
+## SetSearchParams Function
+
+The second element of the tuple is a function that can be used to update the search params. It accepts the same types as `defaultInit` and will cause a navigation to the new URL.
+
+```tsx
+let [searchParams, setSearchParams] = useSearchParams();
+
+// a search param string
+setSearchParams("?tab=1");
+
+// a short-hand object
+setSearchParams({ tab: "1" });
+
+// object keys can be arrays for multiple values on the key
+setSearchParams({ brand: ["nike", "reebok"] });
+
+// an array of tuples
+setSearchParams([["tab", "1"]]);
+
+// a URLSearchParams object
+setSearchParams(new URLSearchParams("?tab=1"));
+```
+
+It also supports a function callback like `setState`:
+
+```tsx
+setSearchParams((searchParams) => {
+  searchParams.set("tab", "2");
+  return searchParams;
+});
+```
+
+## Notes
+
+Note that `searchParams` is a stable reference, so you can reliably use it as a dependency in `useEffect` hooks.
+
+```tsx
+useEffect(() => {
+  console.log(searchParams.get("tab"));
+}, [searchParams]);
+```
+
+However, this also means it's mutable. If you change the object without calling `setSearchParams`, its values will change between renders if some other state causes the component to re-render and URL will not reflect the values.