Please see the "known issues" below before using.
I successfully used this on OS X 10.11 El Capitan. It probably does not work on earlier versions of OS X.
//
// notes-import.scpt
// Steven Frank <[email protected]>
//
// Import a folder full of HTML or text files into Notes.app.
// Crude, but better than nothing. Maybe?
//
// Usage:
// - Open this file in Script Editor
// - Change Script Editor language popup from AppleScript to JavaScript
// - Run
// - Select folder containing files to import
//
// Known issues:
// - Attachments don't get imported
// - Formatting/HTML is not preserved
// - No idea how text encoding is handled
// - File extension should be stripped from title of new note
//