feat: support $XDG_CONFIG_HOME

[paro-paro]

🆒 Your use case

Nuxt devtools currently places local options under the user's $HOME directory.

It would be great if it could support XDG Spec the same way as nuxt does, which places the .nuxtrc file under $XDG_CONFIG_HOME if specified, preventing the pollution of the home dir.

🆕 The solution you'd like

~/.nuxt/devtools is placed under the appropriate OS directory ($XDG_CONFIG_HOME)

🔍 Alternatives you've considered

I guess is kinda related to #487

ℹ️ Additional info

Just a big thanks for all your amazing work within the vue/vite/nuxt communities. Your work is absolutely outstanding.

[paro-paro]

I have a PR ready in case you want to check it out