This is a good opensource text editor and IDE, we currently have a simple extension that enables syntax hilighting for Lua blocks embedded in HTML (views). This does not yet support code hints nor syntax hilighting for macros. Use the Extension Manager in Brackets to install, or download.
By default there is no file association enabled for automatic syntax selection, as Moonstalk views use the standard { "language.fileExtensions":{"html":"moonstalk"} }