Add support for automatic reloading the config when it has been changed

[dolfje]

No description provided.

[muesli]

Thanks for this! General recommendation when getting started with Go: make sure your IDE/editor uses gofmt (comes with Go!) to automatically format the code for you. This fixes several indentation issues for you and makes coding in Go a lot more fun, promised. Check out vim-go for vim or the Go extension for VSCode! Using another editor? Let me know and I'll point you in the right direction.

Alternatively you can also run this manually on the command line:

gofmt -w *.go

[muesli]

Careful, Println doesn't expect formatting directives like %s. You'll have to use Printf here and finish it with a \n for a newline.

[muesli]

Make sure to check the error assignments for this line and the one below. Two options here:

1. Consider this feature optional, and if an error occurs while setting up the file-watcher, we continue without config monitoring
2. Propagate the error, so we can display an error to the user:

if err != nil {
    return nil, err
}