[README] Improve installation guide

README.md

@@ -64,8 +64,63 @@ Symfony Flex, it's much quicker! :)
 
 4. Override repositories
 
- As shown [here](tests/Application/Doctrine/ORM)
- and [here](tests/Application/config/packages/_sylius.yaml).
+ 1. Create repository classes
+ ```bash
+ mkdir src/Repository
+ touch src/Repository/CustomerRepository.php
+ touch src/Repository/ProductVariantRepository.php
+ ```
+ 2. Paste the following content to the `src/Repository/CustomerRepository.php`:
+ ```php
+ <?php
+ 
+ declare(strict_types=1);
+ 
+ namespace App\Repository;
+ 
+ use Sylius\AdminOrderCreationPlugin\Doctrine\ORM\CustomerRepositoryInterface;
+ use Sylius\AdminOrderCreationPlugin\Doctrine\ORM\CustomerRepositoryTrait;
+ use Sylius\Bundle\CoreBundle\Doctrine\ORM\CustomerRepository as BaseCustomerRepository;
+ 
+ final class CustomerRepository extends BaseCustomerRepository implements CustomerRepositoryInterface
+ {
+ use CustomerRepositoryTrait;
+ }
+ ```
+ 3. Paste the following content to the `src/Repository/ProductVariantRepository.php`:
+ ```php
+ <?php
+ 
+ declare(strict_types=1);
+ 
+ namespace App\Repository;
+
+ use Sylius\AdminOrderCreationPlugin\Doctrine\ORM\ProductVariantRepositoryInterface;
+ use Sylius\AdminOrderCreationPlugin\Doctrine\ORM\ProductVariantRepositoryTrait;
+ use Sylius\Bundle\CoreBundle\Doctrine\ORM\ProductVariantRepository as BaseProductVariantRepository;
+ 
+ final class ProductVariantRepository extends BaseProductVariantRepository implements ProductVariantRepositoryInterface
+ {
+ use ProductVariantRepositoryTrait;
+ }
+ ```
+ 4. Configure repositories in `config/packages/_sylius.yaml`:
+ ```diff
+ sylius_customer:
+ resources:
+ customer:
+ classes:
+ model: App\Entity\Customer\Customer
+ + repository: App\Repository\CustomerRepository
+ 
+ sylius_product:
+ resources:
+ product_variant:
+ classes:
+ model: App\Entity\Product\ProductVariant
+ + repository: App\Repository\ProductVariantRepository
+ ```
+
 
 ## Extension points