[Sync EN] Yar: add protocol chapter, PIE installation and richer examples

[github-actions]

PR: https://github.com/php/doc-en/pull/5815 (2026-08-29)

Файлы RU для обновления

• reference/yar/book.xml
• reference/yar/constants.xml
• reference/yar/examples.xml
• reference/yar/setup.xml
• reference/yar/yar-concurrent-client.xml
• reference/yar/yar-server.xml
• reference/yar/yar_client/call.xml
• reference/yar/yar_client/construct.xml
• reference/yar/yar_client/setopt.xml
• reference/yar/yar_client_exception/gettype.xml
• reference/yar/yar_concurrent_client/call.xml
• reference/yar/yar_concurrent_client/loop.xml
• reference/yar/yar_concurrent_client/reset.xml
• reference/yar/yar_server/construct.xml
• reference/yar/yar_server/handle.xml
• reference/yar/yar_server_exception/gettype.xml

Новые файлы EN (ещё не переведены)

• reference/yar/protocol.xml
• reference/yar/versions.xml
• reference/yar/yar_client/getopt.xml