Add default config generation if no config found

[SmilingNavern]

For issue #22
I am not quite sure about implementation. I've tried to found a way to ask viper if there is config file, but found none. So it's a glob checking here for a file. Maybe should move some constants like 'yml' and 'config' to variables.

[d-rk]

You can check whether the config file exists with something like this:

if err := viper.ReadInConfig(); err != nil {
    if _, ok := err.(viper.ConfigFileNotFoundError); ok {
        // Config file not found; ignore error if desired
    } else {
        // Config file was found but another error was produced
    }
}

[SmilingNavern]

@random-dwi hi. Yeah, i thought about it, but i am not sure if this is good approach because there can be side effects of readinconfig.

What do you think i should do? Generate config in error section?

[ghost]

@SmilingNavern thats why the code block checks for the specific error ConfigFileNotFoundError and only in this case the default config should be generated.

[SmilingNavern]

@dwi-di understood, i will rewrite it. Thanks.

[SmilingNavern]

I've rewritten it. Check please

[ghost]

Looks good 👍
I added some minor changes for the error handling

[SmilingNavern]

Cool, thank you for review.