Website: redundant alternative text for SVGs, account dropdown incorrect ARIA, unnecessary role="button" on buttons

[patrickhlauke]

(as discussed in person with @miketaylr the other week) the various SVGs used on the site have duplicate/triplicate alternative text. in general:

• if they're purely decorative, don't include any extra <title> or any text in the <use></use> elements, set aria-hidden="true" to be safe
• if they're part of a control (like a button) that already has a name/label (e.g. text content, an existing aria-label, or similar) they're decorative, so see above

while looking over this issue, I also stumbled across a few other things:

• a few invalid aria-role="hide" attributes?
• redundant role="button" on <button> elements
• aria-pressed is used for the account dropdown in the header. but it's then updated (true/false) not on the button itself, but its parent <li> element by the script. also, aria-expanded is probably more appropriate.

[miketaylr]

Fixed by 958bac4.

❤️