Clarify that <fieldset> only uses the disabled attribute
Clarify that <fieldset> only uses the disabled attribute

BS3 commits: 0f6fab0fd0c8217b43f0599c795098ad78b82e1f

todc/todc-bootstrap,ztx1491/todc-bootstrap,mozillo/todc-bootstrap,up2vs/todc-bootstrap,2947721120/todc-bootstrap,todc/todc-bootstrap,aaroncnhk/todc-bootstrap,2947721120/googlebt4,todc/todc-bootstrap