Unify image width to 600; use flat-square badges on 0.3B

Remove <br> to keep badges in one line

Remove SPGISpeech 2.0 arxiv link

Restore SPGISpeech 2.0 arxiv link in table

Fix links and add datasets field

Replace badge links with text links

Add Tech Report / Code / Model / 1B badge row

Unify citation; update tags

Rename RAON-TTS to Raon-OpenTTS throughout README

initial commit