added Thai language in main README

README.md

@@ -101,6 +101,7 @@ Our client library is modular. Each sub-library is a standalone implementation f
 - [Spanish / Español](/i18n/README.es.md)
 - [Simplified Chinese / 简体中文](/i18n/README.zh-cn.md)
 - [Swedish / Svenska](/i18n/README.sv.md)
+- [Thai / ไทย](/i18n/README.th.md)
 - [Traditional Chinese / 繁体中文](/i18n/README.zh-tw.md)
 - [Turkish / Türkçe](/i18n/README.tr.md)
 - [Ukrainian / Українська](/i18n/README.uk.md)