highlighting of multiline strings treats any `"""` as the end of the string instead of ending a multi-line string on a `"""` that only has whitespace proceeding it

[codyps]

Example:

defmodule Foo do
   @moduledoc """
   Whoops
   Something
   Bar"""

   @it true

   @doc """correct
   """
   def baz, do: @it
end

Currently shows highlighting that indicates the moduledoc multi-line string stops at Bar""" in highlighting, but in fact it ends the line before def baz at the """ on that line.

This is probably because the syntax file is missing the ^ anchor for the end attribute:

vscode-elixir-ls/syntaxes/elixir.json

Lines 31 to 44 in d60e7b7

	{
	"begin": "@(module|type)?doc\\s*(~s)?\"\"\"",
	"comment": "@doc with interpolated heredocs",
	"end": "\\s*\"\"\"",
	"name": "comment.documentation.heredoc.elixir",
	"patterns": [
	{
	"include": "#interpolated_elixir"
	},
	{
	"include": "#escaped_char"
	}
	]
	},

This is potentially an issue for some other cases of """, in that all the end attributes should likely have the ^ anchor to ensure the entire proceeding line is empty. It appears that only the 2 moduledoc entries are missing the ^.