How to use 'phoenix-heex' templates in VSCode

[mtremsal]

For auto-formatting heex.html files, I wasn’t able to rely on any of the plugins listed in the table, but Beautify works well-enough after adding phoenix-heex to its config file:

  "beautify.language": {
    "js": {
      "type": ["javascript", "json"],
      "filename": [".jshintrc", ".jsbeautifyrc"]
      // "ext": ["js", "json"]
      // ^^ to set extensions to be beautified using the javascript beautifier
    },
    "css": ["css", "scss"],
    "html": ["htm", "html", "phoenix-heex"]
    // ^^ providing just an array sets the VS Code file type
  }