Add a11y text to logo

Author: zachleat

src/site/_includes/header.njk

@@ -15,7 +15,8 @@
 
 <header class="page-header sm:flex sm:flex-col sm:h-screen">
   <a href="/" class="block text-white hover:text-pink-900 mx-8 py-8">
-    <svg role="img" aria-label="Jamstack" aria-hidden="true" focusable="false" width="163" height="31"><use xlink:href="#logo-jamstack"></use></svg>
+    <svg role="img" aria-hidden="true" focusable="false" width="163" height="31"><use xlink:href="#logo-jamstack"></use></svg>
+    <span class="sr-only">Jamstack</span>
   </a>
   <details open data-force-state
     data-force-state-closed="(max-width: 39.9375em)"