docs(readme): bigger language pills, tighter gap, breathing room inside

- height 36 -> 40 so glyphs read clearly without a magnifier
-    gap between pills -> single   so the row stays
  compact
- one leading + trailing %20 space inside each badge label so the
  text doesn't kiss the pill edges

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>