feat: add rerender as an alias for update (#149)

<!-- Please provide enough information so that others can review your pull request. -->
<!-- Keep pull requests small and focused on a single change. -->

### Summary

Users of `react-testing-library` use `rerender` wording instead of `update`. Let's make it easier for them by aliasing it.
See: https://testing-library.com/docs/react-testing-library/api#rerender

### Test plan

Added cases for JS tests and TS typings

typings/__tests__/index.test.tsx

@@ -99,6 +99,7 @@ const debugFn = tree.debug();
 const debugFnWithMessage = tree.debug('my message');
 
 tree.update(<View />);
+tree.rerender(<View />);
 tree.unmount();
 
 // fireEvent API tests

typings/index.d.ts

@@ -43,6 +43,7 @@ export interface RenderOptions {
 
 export interface RenderAPI extends GetByAPI, QueryByAPI {
   update(nextElement: React.ReactElement<any>): void;
+  rerender(nextElement: React.ReactElement<any>): void;
   unmount(nextElement?: React.ReactElement<any>): void;
   toJSON(): ReactTestRendererJSON | null;
   debug(message?: string): void;