format list to resemble kubectl outputs

[mxyng]

• Add CURRENT header value
• No newline before printing table

[jmorganca]

Since some destinations in the future may not support a "current" context, should we avoid making this a full column for all destinations? An alternative some products use is adding a * after the name (see below for an example – docker context ls).

NAME            DESCRIPTION                               DOCKER ENDPOINT                                 KUBERNETES ENDPOINT                      ORCHESTRATOR                                                
default *       Current DOCKER_HOST based configuration   unix:///var/run/docker.sock                     https://localhost:8443/proxy (default)   swarm

[jmorganca]

Leaving as-is is also an option: several tools also use the star without a header (e.g. git branch) and I think it's become a familiar pattern to mean "current":

$ git branch
  lightweight
  lint
* list-roles
  local-fix
  lock-login

[mxyng]

That's a good point. For the first point, I was thinking we would have different sections for different destinations, similar to kubectl when you pass get all. In that case, each section has different headers. So for Kubernetes, there will be CURRENT and NAMESPACE columns while for something like SSH there will be an ADDRESS column.

The counterpoint I would have for the git case is that git doesn't have headers at all. If we omit headers from our output, it would look similar.

The main goal of this change is to mimic the kubectl config get-contexts output which users should be familiar with if they're using Kubernetes

[jmorganca]

Sounds good! Wouldn't over-rotate on kubectl familiarity (it's not an easy tool to use in general) but I do think this is a good edit!

[jmorganca]

Optional comment to consider as we add more destinations