Add SVG flags for France, Hong Kong, Japan, South Korea, Russia, and the United States

- Added France flag (fr.svg) with three vertical stripes: blue, white, and red.
- Added Hong Kong flag (hk.svg) featuring a red background with a white flower emblem.
- Added Japan flag (jp.svg) with a white field and a red circle in the center.
- Added South Korea flag (kr.svg) showcasing a white background with a central yin-yang symbol and four black trigrams.
- Added Russia flag (ru.svg) with three horizontal stripes: white, blue, and red.
- Added United States flag (us.svg) with red and white stripes and a blue canton featuring stars.

static/vendor/flags/4x3/jp.svg

@@ -0,0 +1,11 @@
+<svg xmlns="http://www.w3.org/2000/svg" id="flag-icons-jp" viewBox="0 0 640 480">
+  <defs>
+    <clipPath id="jp-a">
+      <path fill-opacity=".7" d="M-88 32h640v480H-88z"/>
+    </clipPath>
+  </defs>
+  <g fill-rule="evenodd" stroke-width="1pt" clip-path="url(#jp-a)" transform="translate(88 -32)">
+    <path fill="#fff" d="M-128 32h720v480h-720z"/>
+    <circle cx="523.1" cy="344.1" r="194.9" fill="#bc002d" transform="translate(-168.4 8.6)scale(.76554)"/>
+  </g>
+</svg>