refactor(eslint-plugin-react-hooks): move rules to rules folder (facebook#32411)

Since the compiler plugin is going to be merged into the hooks plugin,
and ultimately decomposed into several more rules, it would be good to
start creating a more traditional folder structure for the plugin. This
change just moves the rules into a `rules` folder.

Co-authored-by: lauren <[email protected]>

Author: michaelfaith

packages/eslint-plugin-react-hooks/README.md

@@ -36,7 +36,7 @@ If you are still using ESLint below 9.0.0, please continue to use `recommended-l
 For [ESLint 9.0.0 and above](https://eslint.org/blog/2024/04/eslint-v9.0.0-released/) users, add the `recommended-latest` config.
 
 ```js
-import reactHooks from 'eslint-plugin-react-hooks';
+import * as reactHooks from 'eslint-plugin-react-hooks';
 
 export default [
   // ...
@@ -67,7 +67,7 @@ If you want more fine-grained configuration, you can instead add a snippet like
 #### Flat Config (eslint.config.js)
 
 ```js
-import reactHooks from 'eslint-plugin-react-hooks';
+import * as reactHooks from 'eslint-plugin-react-hooks';
 
 export default [
   {

packages/eslint-plugin-react-hooks/src/index.ts

@@ -4,8 +4,8 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-import RulesOfHooks from './RulesOfHooks';
-import ExhaustiveDeps from './ExhaustiveDeps';
+import RulesOfHooks from './rules/RulesOfHooks';
+import ExhaustiveDeps from './rules/ExhaustiveDeps';
 import type {ESLint, Linter, Rule} from 'eslint';
 
 // All rules