add removal of .help-inline to the migration guide; fixes 12539
add removal of .help-inline to the migration guide; fixes 12539

BS3 commits: d8bb6c29870059d7d785ddb3340964f1bba72ed6

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