More options to turn off markdown and sync the markdown setting across the app and the extension

I agree with halb

Really the default should be Markdown OFF. So, for example, that basic functionality like plain text in all the 1Password browser extensions can be rendered correctly, instead of the current situation of having it always render with MD enabled without the basic option to disable MD in these extensions - thus screwing-up text display for all non-MD users (likely either the majority –or certainly a large minority– of 1P users, I'd expect).

That's how plain text in extensions used to work a couple of versions ago.