Shellfirm fails to create config dir if neither ~/.config nor $XDG_CONFIG_HOME exists

[liafonx]

@gaoDean this is the change as @roadkell wrote here,

1. if .shellfirm folder is exists int the from the previous version, the folder keep and shellfirm works with that folder

2. if the folder does not exists

   • checks if the $XDG_CONFIG_HOME is set

   • default his path: Some($HOME/.config)

You can see the PR here: https://github.com/kaplanelad/shellfirm/pull/87/files

Originally posted by @kaplanelad in #67

On a fresh machine where neither $XDG_CONFIG_HOME nor ~/.config exists, Shellfirm errors out with
Loading config error: could not create folder: No such file or directory (os error 2)

It should create $HOME/.config itself in this situation.