docs: Use ApiLink component for API reference link in upgrading guide

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: vdusek

docs/04_upgrading/upgrading_to_v2.md docs/04_upgrading/upgrading_to_v2.mdxdocs/04_upgrading/upgrading_to_v2.md renamed to docs/04_upgrading/upgrading_to_v2.mdx

@@ -4,6 +4,8 @@ title: Upgrading to v2
 description: Breaking changes and migration guide from v1 to v2.
 ---
 
+import ApiLink from '@site/src/components/ApiLink';
+
 This page summarizes the breaking changes between Apify Python API Client v1.x and v2.0.
 
 ## Python version support
@@ -41,4 +43,4 @@ Some modules have been restructured.
 
 ### Errors
 
-- Error classes are now accessible from the public `apify_client.errors` module. See the [API documentation](https://docs.apify.com/api/client/python/reference/class/ApifyApiError) for a complete list of available error classes.
+- Error classes are now accessible from the public `apify_client.errors` module. See the <ApiLink to="class/ApifyApiError">`ApifyApiError`</ApiLink> API reference for a complete list of available error classes.