Add upgrade docs

.gitignore

@@ -10,4 +10,4 @@ phpunit.xml
 psalm.xml
 vendor
 .php-cs-fixer.cache
-
+!docs

README.md

@@ -24,6 +24,10 @@ You can install the package via composer:
 composer require vormkracht10/kvk-api
 ```
 
+## Upgrade guide
+
+See the [upgrade guide](docs/upgrade.md) for more information on what has changed recently.
+
 ## Usage
 
 > Note: if you don't have an API key yet, get yours at the [developer portal](https://developers.kvk.nl/) of the Chamber of Commerce

docs/upgrade.md

@@ -0,0 +1,62 @@
+# Upgrading from v1.x to v2.x
+
+## Changes in Search Results
+
+In the new version, the search results have been expanded to include more detailed information. The Company object now contains the following data:
+
+-   KvK number
+-   Establishment number
+-   Tradename
+-   Address(es) (including type, full address, street, house number, zip code, city, and country)
+-   Website(s)
+
+## New Search Methods
+
+1. Search by KvK Number
+   The new version introduces the ability to search by KvK number:
+
+```php
+$companies = $kvk->searchByKvkNumber('12345678');
+```
+
+2. Search by RSIN
+   You can now search by RSIN (Rechtspersonen en Samenwerkingsverbanden Informatienummer):
+
+```php
+$companies = $kvk->searchByRSIN('12345678');
+```
+
+## Pagination Support
+
+The new version adds support for pagination in search results:
+
+```php
+$kvk->setPage(2);
+$kvk->setResultsPerPage(20);
+```
+
+Alternatively, you can pass these parameters directly to the search method:
+
+```php
+$companies = $kvk->search('Vormkracht10', [
+    'pagina' => 1,
+    'resultatenPerPagina' => 10
+]);
+```
+
+## Updating dependencies
+
+```bash
+{
+    "require": {
+        "vormkracht10/kvk-api": "^2.0"
+    }
+}
+```
+
+Then run `composer update` to install the new version.
+
+## Breaking changes
+
+-   The structure of the Company object has changed. Make sure to update any code that relies on the specific structure of the search results.
+-   The method signatures for creating the client and performing searches have been updated. Review and update your code accordingly.