feat: Add `rss` icon

Closes #13

icons/rss.svg

+<svg
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <path d="M4 11a9 9 0 0 1 9 9" />
+  <path d="M4 4a16 16 0 0 1 16 16" />
+  <circle cx="5" cy="19" r="1" />
+</svg>