Improve /terminal-setup output format #325

The new /terminal-setup slash command installs some keybindings into the keybindings.json file, but it doesn't respect the existing comments in this JSONC or JSON5 document, so after executing the command, the keybindings.json is reformatted and without any comments.

I think this slash command could be improved:

• Show a warning to the user about the removal of the comments, reformatting, and sorting of the keybindings, with a prompt if the user wants to continue.
• Prompt for creating first a backup of the existing keybindings.json file with a date+time -> keybindings.json.bak-$(date +%Y-%m-%d_%H:%M:%S).
• and use a JSON5 library or JSONC library, which can preserve comments in json documents with comments.
• Create or show a documentation with the keybindings setup for the terminal setup, which she/he can do manually to its keybindings.json file.
• Or let AI do it 😆, but warn that you pay with a premium request 💃.

Originally posted by @tobiashochguertel in #14