Add settings option to disable format on save

[rinarakaki]

Since we cannot configure the formatting of buf, we want an option to disable the format on save behaviour of the buf VSCode extension at least. I hope you consider it. Thank you.

[nicksnyder]

Hi @rinarakaki , you can disable the format on save behavior by adding this to your user settings or workspace settings file:

    "[proto]": {
        "editor.formatOnSave": false
    },