Update introduction documentation and README to consistently refer to
OpenReader as "open-source" and highlight its multilingual capabilities.
Refine language segmentation example in multilingual sample text and
expand test coverage for language settings. Adjust TTS segment manifest
to normalize language tags, improve document language update logic, and
fix provider/model compatibility checks for instructions and language
input. Enhance reliability of language support detection for TTS
generation and Replicate provider integration.
379e5082f0