HTMLObjectElement has alt attribute only in Internet Explorer (and edge?)

[HolgerJeromin]

TypeScript Version: 2.6.3

lib.dom.d.ts has alt attribute for HTMLObjectElement:
https://github.com/Microsoft/TypeScript/blob/5b5a00745997768fad7d3a4c98931af179fa277a/lib/lib.dom.d.ts#L5981-L5986

This is not in HTML Standard, Firefox or Chrome available.

[mhegazy]

PRs welcomed. You can find more information about contributing lib.d.ts fixes at https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md#contributing-libdts-fixes.

[benbraou]

@mhegazy I would like to work on this issue