kimito_en: use columns shorthand for side-by-side lyrics

Replace the hand-written {=html} flex/poem block with the new ```columns
fenced shorthand (JP and EN split by ===). The pipeline's post-Pandoc
transform expands it to the same wikitext, so the rendered page is
unchanged — just far cleaner to author.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

kairo/kimito_en.md

@@ -13,9 +13,7 @@ release_date: 2026-06-14
 The classic. Old working notes in [another page](Looking_into_You_and_me_\(ry_and_a_brand_new_translation).  
 
 ## Lyrics
-```{=html}
-<div style="display:flex; gap:3em; align-items:flex-start">
-<poem>
+```columns
 <b>君と私と穏やかな旅</b>
 
 いつか見た夢の話
@@ -56,8 +54,7 @@ The classic. Old working notes in [another page](Looking_into_You_and_me_\(ry_an
 あの日の記憶の欠片
 いつか思い出すよ
 この旅路を
-</poem>
-<poem>
+===
 <b>You and me and a gentle journey</b>
 
 You know there was a dream I had long ago
@@ -95,6 +92,4 @@ There won’t be not such meaningful events left
 
 
 To go across the borderline 
-</poem>
-</div>
 ```