🐛 Fix default config directory permission to 0755

[nikukyugamer]

Creating config directory initially, config file isn't created because permission denied as below.

$ deepl-translate-cli
2022/03/12 18:12:28 open /home/USERNAME/.config/deepl-translate-cli/setting.json: permission denied

So I fixed it.

After fixed, config file was created correctly.

$ deepl-translate-cli
2022/03/12 18:25:06 Not exists such file. /home/USERNAME/.config/deepl-translate-cli/setting.json
        auto make it, please write it.
exit status 1

Note:

~/.config/deepl-translate-cli directory permission is always 0777 but ~/.config/deepl-translate-cli/setting.json permission depends on user's umask.

[Omochice]

I think it's no problem to merge this PR because it works fine in my pc too.
Thanks!