updates, documentation, tests

Author: Alex Lohr

README.md

@@ -101,6 +101,8 @@ const { result } = renderHook(createResult);
 expect(result).toBe(true);
 ```
 
+If you are using a `wrapper` with `renderHook`, make sure it will **always** return `props.children` - especially if you are using a context with asynchronous code together with `<Show>`, because this is required to get the value from the hook and it is only obtained synchronously once and you will otherwise only get `undefined` and wonder why this is the case.
+
 ⚠️ Solid.js supports [custom directives](https://www.solidjs.com/docs/latest/api#use___), which is a convenient pattern to tie custom behavior to elements, so we also have a `renderDirective` call, which augments `renderHook` to take a directive as first argument, accept an `initialValue` for the argument and a `targetElement` (string, HTMLElement or function returning a HTMLElement) in the `options` and also returns `arg` and `setArg` to read and manipulate the argument of the directive.
 
 ```ts