Add a traffic field to custom servers

[dban0001]

Is your feature request related to a problem? Please describe. Custom servers don't have a traffic indicator. For example, DigitalOcean servers show this:

However, custom servers don't have this indicator, because Outline does not know about a traffic limit:

Many server providers also have a traffic limit.

Describe the solution you'd like It would be extremely useful if you could add an optional server traffic limit field when adding a custom server, or add it to the json object to initialize the server. In this way, people can manually add a limit when they know a server has one, and Outline doesn't need to add hundreds of server providers to use the traffic limit feature.

[alalamav]

Thanks for the feedback, @dban0001. We'll take it into consideration. For other users seeing this issue, please upvote it if this would be useful for you so we can take the demand into acccount when prioritizing.

[sbruens]

Moving this to the new repo home for Outline Manager.