Feature Description:

I can add a folder called data in root directory of vscode, then it will become portable, and store all data in that folder. I hope I can do that in theia as well as vscode.

More information added by an Eclipse Theia maintainer:

Portable mode permits having vscode save all it's data in one of its own a sub-folder, instead of the usual places (user's home, user's config directory, etc). That makes it super easy to copy/move all user data to another vscode installation, preserving everything the user changed (preferences, history, installed extensions, ...).

Portable mode can be used only with the "zip" distribution of vscode:

"Portable mode is supported on the ZIP download for Windows, and the TAR.GZ download for Linux, as well as the regular Application download for macOS"