Dedicated page for payment options

For easier way to direct people to drop money for being around

- Stripe
- SumUp Widget
- https://developer.sumup.com/docs/online-payments/tools/card-widget/
```

SumUpCard.mount({
id: 'sumup-card',
checkoutId: '2ceffb63-cbbe-4227-87cf-0409dd191a98',
onResponse: function (type, body) {
console.log('Type', type);
console.log('Body', body);
},
});

```

- #92 + set on-chain identity best
- Fiat an on-ramp for DOT on the page? 😅

Currently we have just
- https://subwork.xyz/membership.html#payment-options

Start by reviewing the existing payment-options section at membership.html#payment-options and the SumUp Widget documentation linked in the issue. Compare the requested Stripe, SumUp, #92 on-chain identity, and DOT on-ramp items, then clarify which belong on the dedicated page. Done should provide the agreed payment options in one dedicated location.

Written by the indexing model from the issue text.