unread num icon

[gjaagcwbomp35]

Sometimes you may be too busy to hear the sound and have no time to read it. When you can handle it, you don't know how many messages are left unprocessed in the intermediate process. Can you add the number of unread messages like this icon prompt like ntfy, It will be a better experience, thank you.

[jmattheis]

Seems like a useful feature. I'm open to accept PRs for this, when the implementation is purely done clientside.

For a serverside implementation, another ticket already exists: #266