1Password secure notes editor

[mrjones2014]

We should be able to load secure notes items into a buffer, set vim.bo.filetype = 'markdown' (since I think 1Password secure notes uses markdown), set the vim.bo.buftype = 'nofile', and edit 1Password secure notes in Neovim.

As for updating, there's one of two approaches we can do, the first one needs some research:

• Write the buffer to /dev/null and set up BufWritePre autocmds to update the secure note in 1Password (important: would need to validate whether writing to /dev/null compromises the security of the note in some way)
• Just use a separate command to update the secure note in 1Password, like :OpWrite or :OpSaveNote` or something like that

This could actually be a really awesome way to use 1Password secure notes. If I can get it working well enough/seamlessly enough it might even replace Notion for me.

[mrjones2014]

After a little research, first option cannot be guaranteed to be secure. It is possible to replace /dev/null with something else if you have administrative privileges. While this is extremely unlikely, we shouldn't even open the possibility.

The buffer must be buftype=nofile and use a separate, dedicated command for updating in 1Password.

@tsyroid thoughts on:

• :OpWrite (possibly with :OpW as a shorthand?)
• :OpSave
• :OpSync (though maybe this should also reload changes from 1Password into the buffer?)
• Something else

[mrjones2014]

Should also wait for #26 so we can update the notes in 1Password asynchronously.

[mrjones2014]

Another idea is we could split note titles on > to make a simulated hierarchy/directory structure and make a 1Password secure notes sidebar.