Bug: Some HTML <pre> elements missing in epub when converting from url

[cykirk]

Describe the bug
Some, but not all, pre elements don't appear in final epub.

To Reproduce
Steps to reproduce the behavior:

1. Use kindle-send to download bash reference manual
   kindle-send -url https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html
2. Inspect epub file section 'Creating Internationalized Scripts' and see that some code snippets are missing.

Expected behavior
All code snips should be rendered.

Screenshots

[cykirk]

Seems like this might be an issue in the go-epub library as I had the same issue when using papeer

[nikhil1raghav]

Issue is with readability, project uses go-readability which is port of mozilla's readability. When you open the same page in firefox reader mode then also that snippet is missing. Need to patch go-readability for this.