fix: a11y in About page

src/components/general/About.svelte

@@ -145,14 +145,14 @@
               <tr class="odd:bg-white even:bg-gray-100">
                 <td>{l.name}</td>
                 <td>
-                  {l.license || "?"}<br /><span
+                  {l.license || "?"}<br /><button
                     class="underline cursor-pointer"
                     on:click={() => {
                       modal_open = true;
                       currentlicense = l.name + "@" + l.version;
                       licensetext =
                         l.licensetext || $_("no-license-text-could-be-found");
-                    }}>{$_("read-license")}</span
+                    }}>{$_("read-license")}</button
                   >
                 </td>
                 <td>