add html style docs to snips

[dtolb]

Overview

Doxygen doesn't define html style comments.

However, for my case I need those to build out.

Code Changes

marker.js

• Adds <!-- to commentOpen regex
• Adds --> to commentClose regex

Tests

marker-test.js

• should slice code between [marker0] with HTML comment <!-- -->
• should slice code between [marker1] with HTML comment <!-- -->
• should slice code between [marker2] with HTML comment <!-- -->

[azu]

Thanks for PR. Looks good to me.

@gdolle What do you think of it?

[gdolle]

@azu ok for me also 👍

[azu]

@gdolle Thanks for confirm it.

@dtolb Release it as https://github.com/azu/gitbook-plugin-include-codeblock/releases/tag/3.1.0