github sync: empty link html contents cannot be parsed #3591
Description
Bug description
When sync documents from github, if the documents contain links with empty href, then the link and the contents is lost in gitbook.
<b>use</b> <a href="">0x1::error</a>; <b>use</b> <a href="">0x1::event</a>; <b>use</b> <a href="">0x1::object</a>; <b>use</b> <a href="">0x1::option</a>; <b>use</b> <a href="">0x1::signer</a>; 