Fix in-page link without target

[YumiChen]

Fix #79

For twitterConnectBtn and fbConnectBtn are not for page navigation( there are event listeners are bound to them instead), remove a tags and move menuitem role item to list items instead

Note. this UI is actually not in accessibility tree for its grandparent has display: none style. We can see if we want to review whether to include these types of issues in the board

[thomassth]

I think if they're supposed to be buttons, <button> would be more suitable?

[YumiChen]

Good point. Was referencing the W3C WAI-ARIA menubar example:
https://www.w3.org/WAI/ARIA/apg/patterns/menubar/examples/menubar-editor/

While both button and li should be accessible, I'll update to use button to align with the ids. Thanks for the suggestion!

[NewJerseyStyle]

Twitter login could have been deprecated, we may consider removing it in future 🤔
I guess until then...