The README says:

but most usual errors are covered (eg. HTML4 style no closing <li>, <td> etc).

These are not errors, nor are they HTML 4 specific.

The end tags have been optional for those elements in every version of HTML since they were introduced.

For example, from the HTML+ spec:

<OL>
	<LI>Wake up
	<LI>Get dressed
	<LI>Have breakfast
	<LI>Drive to work
</OL>

and from the current specification:

An li element's end tag can be omitted if the li element is immediately followed by another li element or if there is no more content in the parent element.

Please correct the documentation.