Handle styling for `.vlist-t2` spans in KaTeX HTML

[rajveermalviya]

Currently KaTeX parser doesn't apply the following styles for vlist spans.

    .vlist-t2 {
        margin-right: -2px;
    }

This will depend on negative margins support.

[gnprice]

I believe these exist only to cancel out a different quirk (a Safari workaround) in the KaTeX HTML and CSS. It seems like the vlist-t2 class appears exactly when a .vlist-s span is present; and the CSS says:

    .vlist-t2 {
        margin-right: -2px;
    }

    .vlist-s {
        // This cell solves Safari rendering problems. It has text content, so
        // its baseline is used for the table. A very small font avoids line-box
        // issues; absolute units prevent user font-size overrides from breaking
        // rendering. Safari refuses to make the box zero-width, so we give it
        // a known width and compensate with negative right margin on the
        // inline-table. To prevent the "width: min-content" Chrome workaround
        // from shrinking this box, we also set min-width.
        display: table-cell;
        vertical-align: bottom;
        font-size: 1px;
        width: 2px;
        min-width: 2px;
    }

So to resolve this issue, we just need to verify that and then add a comment in the code explaining it.