[Feature] support xdg-/freedesktop specification on linux

[fabiscafe]

Feature description

On Linux we have a specification for desktop-app-configurations. We dont put everything to $HOME.

https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html

Motivation

Supporting xdg/freedesktop specification is critical nowadays. Many containerized formats like flatpak and snap make use of it. Backup software might not include out-of-spec directories by default and certain software will ignore/block out-of-spec dirs

Alternatives

No response

Additional context

No response

[lencx]

The entire .chatgpt directory is the configuration of the application, and they correspond to the different functional implementations.

[yixinBC]

There is a trade-off: focus on developing some platform-specific functions and improvements(with a lot of compatibility issues and platform-specific code) or give priority to developing cross-platform functions and improvements.At the current stage (early stage of the project), we may always prefer the latter. Of course, we welcome anyone to open PRs to implement any exciting functions or improvements for this application at any time,whether platform-specificed or not.