fix: fix PGP link da /pgp a /public_key.gpg (era 404)

manifesto.html

@@ -186,7 +186,7 @@ footer .built{font-size:13px;color:var(--muted);margin-top:8px}
       <a href="https://bitcoin-after.life">bitcoin-after.life</a>
       <a href="mailto:info@bitcoin-after.life">info@bitcoin-after.life</a>
       <a href="https://x.com/BitcoinAfterLif">@BitcoinAfterLif</a>
-      <a href="https://bitcoin-after.life/pgp">PGP Key</a>
+      <a href="https://bitcoin-after.life/public_key.gpg">PGP Key</a>
       <a href="https://bitcoin-after.life/gitea/bitcoinafterlife">Source Code</a>
     </div>
     <div class="built">Built with ₿itcoin. No FIAT was used in the making of this protocol.</div>