Implement domain validation for client-side input ✅

### Reproduce the issue ⚡️

Enter the value "ghost" into the input box. On form submission the request is subsequently processed and fails as this is not a legitimate domain.

#### Photographic evidence 📷

### Suggested improvements 🔨

Implement client-side logic to validate the input and prevent form submission if the input does not take the form of a legitimate domain. This is most likely to take the form of a Regular Expression that validates the input and enables form submission once satisfied.

Subsequently, this will leave the error message for domain forms that most likely aren't actually live or legitimate domain requests: