Feature adding and UI adjustment

Added Preshared-Key to all configuration

src/templates/qrcode.html

@@ -1 +1 @@
-{{ qrcode("[Interface]\nPrivateKey = "+i['private_key']+"\nAddress = "+i['allowed_ip']+"\nMTU = "+i['mtu']+"\nDNS = "+i['DNS']+"\n\n[Peer]\nPublicKey = "+i['public_key']+"\nAllowedIPs = "+i['endpoint_allowed_ip']+"\nPersistentKeepalive = "+i['keepalive']+"\nEndpoint = "+i['endpoint']) }}
+{{ qrcode(i) }}