Misleading warning for minlength attributes on input elements

[orlitzky]

$ tidy index.html
line 218 column 13 - Warning: <input> proprietary attribute "minlength"
line 240 column 13 - Warning: <input> proprietary attribute "minlength"
line 304 column 13 - Warning: <input> proprietary attribute "minlength"
Info: Document content looks like HTML5
Tidy found 3 warnings and 0 errors!

This is no longer a proprietary attribute however:

• https://html.spec.whatwg.org/multipage/input.html#the-maxlength-and-minlength-attributes
• https://www.w3.org/TR/2021/NOTE-html53-20210128/sec-forms.html#the-maxlength-and-minlength-attributes
• https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/minlength (shows browser compatibility)