The plan says "1 item, 1 pack", not "1 items, 1 packs" (#180)

ddiff --git a/server/http/pages.js b/server/http/pages.js
iindex cecd054..1030622 100644
---- a/server/http/pages.js
++++ b/server/http/pages.js
@@@ -328,7 +328,7 @@ ${table(['Item', 'Packs', 'Where', 'Cost'], plan.shopping_list.map((i) => [html`
  ${plan.menu.map((d) => html`<section class="plan-day"><h3>Day ${d.day}</h3>
  <ul>${[['breakfast', 'Breakfast'], ['lunch', 'Lunch'], ['dinner', 'Dinner'], ['snack', 'Snack']].map(([slot, label]) => html`<li><b>${label}:</b> ${d[slot].join(', ') || '—'}</li>`)}</ul></section>`)}
  <h2>Food groups</h2>
--${table(['Group', 'A day, at least', 'In the plan', 'Cost'], plan.group_coverage.map((g) => [g.name, `${g.daily_min_g} g`, g.covered ? `${g.items} items, ${g.packs} packs` : '—', money(g.cost)]))}
++${table(['Group', 'A day, at least', 'In the plan', 'Cost'], plan.group_coverage.map((g) => [g.name, `${g.daily_min_g} g`, g.covered ? `${g.items} item${g.items === 1 ? '' : 's'}, ${g.packs} pack${g.packs === 1 ? '' : 's'}` : '—', money(g.cost)]))}
  ${plan.notes.map((n) => html`<p class="muted small">${n}</p>`)}`;
      }