1. Install Visual Studio Code.
2. Install "Lua Language Server" extension in VSC (I use that one published by sumneko).
3. Download Moose source code ( https://github.com/FlightControl-Master/MOOSE/releases ).
4. Add that folder (from downloaded source code archive ) to your VSC Workspace: "..\Moose Development\Moose".
5. Create .lua file in that workspace.
6. Enjoy.
VSC with Lua Language Server treats all workspace .lua files as dictionaries, that's why I recommend you customize the Moose folder. I use everything myself and work very well. VSC at startup extends the LUA dictionaries with the content of the .lua files used in the workspace, which may take a while. For some reasons, some files are skipped (displayed "green") - just open them for a moment.
Pt. 5 is crucial - "Menu:> File> New File" does not work until you save the file.
PS: sorry for my google-translate English! :D
Thank You, sumneko, for Your great job!
https://github.com/sumneko