docs: fix link for unsupported chars in usernames

for #1005

templates/docs.html

@@ -311,7 +311,7 @@ <h3 id="general">Using</h3>
 <li>If you're looking at your bridged account in the fediverse, Bridgy Fed only delivers your posts to fediverse instances where you have at least one follower. (This is how the fediverse works in general.)
 <li>If you're on Bluesky, do you have the <a href="https://bsky.app/profile/safety.bsky.app/post/3khhw7s3rtx2s">"hide account in logged out view"</a> setting enabled? Bridgy Fed interprets that as opting out and won't bridge your account while it's on.</li>
 <li>If you're on the fediverse, your server might be blocking or limiting Bridgy Fed. Check your server's <em>About</em> page to see if <code>bsky.brid.gy</code> or <code>brid.gy</code> are in the <em>Moderated servers</em> section. If they are, you can ask your server admin to reconsider, and include a link to this page for more details.
-<li>If you're on the fediverse, and your username - ie the first part of your handle, before the middle `@` character - begins or ends with <code>_</code>, <code>-</code>, or <code>~</code>, or contains any non-alphanumeric characters, ie anything other than <code>A-Z</code> <code>a-z</code> <code>0-9</code> <code>_</code> <code>-</code> <code>~</code>, Bridgy Fed can't currently bridge your account. Sorry. This may change in the future; <a href="https://github.com/snarfed/bridgy-fed/issues/982">follow the GitHub issue for details</a>.
+<li>If you're on the fediverse, and your username - ie the first part of your handle, before the middle `@` character - begins or ends with <code>_</code>, <code>-</code>, or <code>~</code>, or contains any non-alphanumeric characters, ie anything other than <code>A-Z</code> <code>a-z</code> <code>0-9</code> <code>_</code> <code>-</code> <code>~</code>, Bridgy Fed can't currently bridge your account. Sorry. This may change in the future; <a href="https://github.com/snarfed/bridgy-fed/issues/1005">follow the GitHub issue for details</a>.
 </ul>
 <p>If none of that helps, <a href="#user-page">check out your user page!</a> It detects and describes common problems with <a href="#web-setup">your setup</a>, and it shows your recent interactions and detailed logs.
 </li>