Docs: Bring the guide up to the Pythonic surface that now exists #34

What

Update docs/guide (bilingual, GitHub Pages) and README / docs/locale/README_ko.md for what landed in #21–#32: the one re-export rule (snake_case names, keywords, signatures; upper-case kept), Modifier chains with snake_case methods, Kotlin objects (Alignment, Arrangement), manifest aliases (Column/Row/Spacer from material3), and the INTENT 5 spellings (Modifier not modifier, Color(...), Spacer(modifier=...)).

Why

The guide still describes several of these as not yet built.

Done when

Every changed page has English and Korean text, tools/check_guide.py reports 0 findings, examples match tests/test_chain.py, and nothing claims a feature that is still pending (app root, TextField, icons, grouped Alignment, real-Compose stubs).