Anyway to activate extension automatically on other files (not only *.txt, *.tab)?

[contributor]

I can do this manually using "Language Mode" in status bar or command pallete, and SongTxt does chord highlighting. But automatic mode would be great to brows many files in folders with non standard extension

[contributor]

It is possible to achieve this behavior using vscode settings json:

    "files.associations": {
        "*.md": "songtxt"
      }

This issue can be closed.