Initial configuration wizard

[whisperity]

trafficstars

Given the plethora of configurable and perhaps-important-for-some feature requests (like default shell, history size, #495, #645, permission bits, etc.), I'd like to see an initial setup wizard, similar to that of Zsh, OMZ or P9k/P10k executed when Contour is started for a user the first time.

It shouldn't ask for EVERY minor configuration from the user, but if a config file is not found, it should ask for the user's input and spawn the config file that way.

The proposed approach would be to hardcode, in Contour's code, a type system and a description field for each (important?) config variable, from which the config file can be automatically generated. And the wizard would ask automatically if a config option is flagged, let's say bool InteractiveConfigureAtFirstStart or something...

Also, it would be important to implement the wizard as a terminal application, and not something graphically clicky. It could even be its own separate binary, contour-config, supplied with the release.

1. If no contour.yaml is found, register this fact, and drop the default configuration into the appropriate location.
2. Start a default shell and immediately run contour-config.

Users could then re-run contour-config interactively any point later in time, as long as contour-config doesn't show the user the hardcoded defaults, or shows both the hardcoded default and the CURRENT config value from the user's actual config file.