Refine about page image section with balanced side-by-side layout

[Copilot]

The climbing and cycling photos were rendered as stacked block elements with mismatched apparent sizes (600px vs 300px native widths), and lacked captions.

Changes

• _pages/about.md: Replaced sequential <figure> blocks with a flex container:
  • flex-wrap: wrap for clean stacking on narrow viewports
  • flex: 1 1 320px; max-width: 420px on each figure to equalize visual sizing regardless of source image dimensions
  • <figcaption> labels beneath each photo
  • width: 100%; height: auto on images so they fill their column responsively

<div style="display: flex; gap: 1.5rem; align-items: flex-start; justify-content: center; flex-wrap: wrap;">
  <figure style="margin: 0; text-align: center; flex: 1 1 320px; max-width: 420px;">
    <img src="...climbing.jpg" alt="Climbing" style="width: 100%; height: auto; display: block;" />
    <figcaption>Climbing</figcaption>
  </figure>
  <figure style="margin: 0; text-align: center; flex: 1 1 320px; max-width: 420px;">
    <img src="...cycling.jpg" alt="Cycling" style="width: 100%; height: auto; display: block;" />
    <figcaption>Cycling</figcaption>
  </figure>
</div>

All other page content is untouched.