Set default URL without using --init

[wndyy]

I think it's too time consuming to set default URL using init flag and going through the configuration process.

I think it'd be useful to have a feature that is similar to git, where you have a command that helps you set the default URL without going through the whole configuration process.

[cvraut]

Sounds like a good idea.

Worth mentioning that u don't have to run whecho --init to use whecho. The init defines the configuration explicitly in front of the user. If the --url flag is passed it doesn't matter if the configuration exists or not. The message is sent to the provided url.

Some users are already familiar with the --init flag, so don't remove the current functionality but add in another option or cmd line argument like whecho --config <key> <value>.

Send me a PR and I can review it.