Checklist

• I have searched the issue tracker for open issues that relate to the same feature, before opening a new one.
• This issue only relates to a single feature. I will open new issues for any other features.

Is your feature request related to a problem?

The folk over at Least Authority have Winden and Destiny as some very good clients for sending using the same Wormhole protocol. This is very useful because they allow to send and revive from a web browser and Android/iOS respectively. However, they do not use the same servers by default and a user would have to manually use these settings:

• AppID: lothar.com/wormhole/text-or-file-xfer
• Rendezvous URL: wss://mailbox.mw.leastauthority.com/v1
• Transit Relay Address: relay.mw.leastauthority.com:4001

Describe the solution you'd like to see.

I'm thinking that we can update the advanced section to use widget.SelectEntry{} instead of widget.Entry{} and provide the Least Authority servers as alternatives without the user having to paste them in manually (also makes it easier to switch between that and the standard settings):

Even though the AppID parameter is the same, I suppose we could add only lothar.com/wormhole/text-or-file-xfer to the options there. I suppose it would be better to also stop putting the defaults in the placeholder text and just have them all in the options list instead.