Handle CommonMark-incompliant multiline HTML comments without clobbering comments in code blocks

[zeke]

markdown-it freaks out on malformed/spec-incompliant multiline HTML comments:

• https://www.npmjs.com/package/cordova-plugin-camera
• https://www.npmjs.com/package/cordova-plugin-device
• https://www.npmjs.com/package/cordova-plugin-contacts
• https://raw.githubusercontent.com/rwaldron/johnny-five/master/README.md
• https://github.com/npm/newww/issues/867

A while back I added some code to marky-markdown that removed HTML comments from strings before passing them to the markdown-it parser. This solved the problem for the above-mentioned READMEs, but introduced new problems in other places. Some READMEs contain HTML comments within code blocks, and those should not be removed. For example:

• https://www.npmjs.com/package/gulp-inject#basic-usage
• https://www.npmjs.com/package/essi#def

There are at least two possible solutions to this:

1. Figure out a way to remove HTML comments that aren't within a code block.
2. Write a custom html_block function for markdown-it

[puzrin]

https://github.com/markdown-it/markdown-it/blob/master/CHANGELOG.md#440--2015-07-18

Should be fixed in markdown-it 4.4.0, you need to upgrade dependency.

[zeke]

👏 Thank you @soldair and @puzrin