Markdown code-block not working on IE 11

[krishna-vempati]

My swagger documentation contains ``` to illustrate code examples, which are not necessarily related to API operations.

The code examples render well on Chrome, Firefox or Safari. However, the rendering fails on IE 11 with the following error:

I am using v1.19.3 to render the documentation. IE version is 11.0.9600.18817.

If there is a workaround to move the code sample to the third column, I can live with that :) Thanks.

[zeroorone-huff]

We have experienced the same issue. The bug in IE11 appears to be caused by using the parentElement function in the HTMLEscape method (https://github.com/Rebilly/ReDoc/blob/master/lib/utils/md-renderer.ts#L11). Using parentNode appears to resolve the issue.

[RomanHotsiy]

@krishna-vempati thanks for the bug report.
@zeroorone13 thanks so much for investigating this!

I will release a new package soon.

[krishna-vempati]

Awesome! Thank you so much. I see you have released 1.20.0 already.