Build with tts feature in releases

[zeozeozeo]

From readme:

Note

By default, Ellama will build with the tts feature OFF. If you need TTS, build with cargo build --features tts.

Note that on Linux, this requires libspeechd (libspeechd-dev) to be installed. TTS is currently not enabled in release builds because of this (cross-compilation complications), see #71

Probably need ndarilek/tts-rs#60 for this