fix(m): correct copy behavior

During development, I:
- used go/ rather than a host for the copied URL
- used navigator.clipboard, which can't be used outside of secure
contexts, and didn't clean up when I changed that

menu/src/html/create/success.html

···
     <p>Your new shortlink is up!</p>
     <p><a href="/{from:url}">{host}/{from}</a> now goes to <a href="{to:attribute}">{to}</a></p>
     <ul>
-      <li>Access it at <a href="/{from:url}">{host}/{from}</a> (<span id="copy" text="go/{from:attribute}" onclick="navigator.clipboard.writeText(this.getAttribute('text')); ">copy</span>)</li>
+      <li>Access it at <a href="/{from:url}">{host}/{from}</a> (<span id="copy" text="{host:attribute}/{from:attribute}">copy</span>)</li>
       <li><a href="/_/create">Create another one</a></li>
       <li><a href="/_/create?from={from:url}&to={to:url}&current={to:url}">Edit it</a></li>
       <li><a href="/_/delete/do?from={from:url}&current={to:url}">Delete it</a></li>