The formatter seems not work with `*.html` files

[bioinformatist]

I don't know how to format *.html files. It may works with early versions of tera-vscode, but seems not work now.

[LitoMore]

See #11. You can use the "editor.defaultFormatter": "vscode.html-language-features" instead.

But the VS Code built-in formatter works like rubbish. It ruined some indents in the code.

cc @karamfd @karuna

Here is a diff example:

{%- macro seo(
-	title="",
-	title_addition="",
-	description="",
-	type="website",
-	is_home=false,
-	is_404=false,
-	is_page=false
-	)
+title="",
+title_addition="",
+description="",
+type="website",
+is_home=false,
+is_404=false,
+is_page=false
+)
%}