feat: add Default config which applies to all servers

[sevenc-nanashi]

This PR adds Default config which applies to all servers, with some extra configuration such as local-editor.

This PR closes #60 .
The configuration file will look like:

default:
  local-editor:
    [
      "C:\\Program Files\\Neovide\\neovide.exe",
      "--no-fork",
      "--server={{SOCKET_PATH}}",
    ]

servers:
  myServer1:
    ...
  myServer2:
    local-editor: ...

[mikew]

Given where ApplyPrecedence is called in the flow, getSshPath isn't applied to it. So in yaml ssh-path: binary would look for a literal executable named binary in your $PATH, and not actually use the default.

[mikew]

Would prefer if this was just []string:

• via cli arg, they're FOO=bar
• via env vars, they're FOO=bar
• via yaml, they're FOO: bar

[mikew]

Ah, more changes are needed to pipe these through is the issue.

[mikew]

Huh, I can see that was was just moved to DRY the yaml -> CLI stuff, so I might have had a bug here. I have $NVRH_CLIENT_SERVER_ENV set in my environment and that's taking precedence over anything in the YAML.

[mikew]

Ah, more changes are needed to pipe these through is the issue.

[mikew]

When adding to this, we need to remove the source from the CLI command, similar to

nvrh/src/client/main.go

Lines 67 to 72 in 720d3d7

	&cli.BoolFlag{
	Name: "use-ports",
	Usage: "Use ports instead of sockets. Defaults to true on Windows [$NVRH_CLIENT_USE_PORTS]",
	// Sources: cli.EnvVars("NVRH_CLIENT_USE_PORTS"),
	Value: runtime.GOOS == "windows",
	},

[mikew]

I went ahead and made those changes, this works a treat, thanks for the PR!