add alt-text to css pseudo elements

[StephDriver]

we have several inline lists that have pseudoelements e.g.

.bar-sep li:not(:last-child)::after {
    content: " | ";
}

we should ensure these (and any others) have appropriate alt text where needed. So something like:

.bar-sep li:not(:last-child)::after {
    content: " | " / "";
}