message: Fix variables syntax highlighting. Closes
diff: @@ -22,11 +22,12 @@ monaco.languages.setMonarchTokensProvider("shell", {
  },
  {
  regex: /@word/,
  - action: {token: "command-name", next: "@command"},
  + action: {token: "command-name", next: "@arguments"},
  },
  ],
  - command: [
  + arguments: [
  [/\s+/, "spaces"],
  + [/\$@variableName/, "variable-name"],
  [/@word/, "argument"],
  [/[=[\]]/, "argument"],
  {
  