Support '===' or '---' headings

[naokazuterada]

Support '===' or '---' headings

+1, it would be great to support === and --- headings

[Parnswir]

It seems, that this issue is present once again:

hello
=====

world
-----

This file produces the following error if you try to insert a TOC before the first heading

Traceback (most recent call last):
  File "...\Sublime Text 3\sublime_plugin.py", line 556, in run_
    return self.run(edit)
  File "MarkdownTOC in ...\Sublime Text 3\Installed Packages\MarkdownTOC.sublime-package", line 39, in run
  File "MarkdownTOC in ...\Sublime Text 3\Installed Packages\MarkdownTOC.sublime-package", line 211, in get_toc
  File "MarkdownTOC in ...\Sublime Text 3\Installed Packages\MarkdownTOC.sublime-package", line 220, in update_anchors
TypeError: unsupported operand type(s) for -: 'str' and 'int'
'cannot find TOC tags'

Doing the same after both headings works.

[naokazuterada]

@Parnswir

I fixed this problem.
Excuse me...and thank your for your quick report.