Templates should pass W3C validation

[jwag956]

Our shipped templates should be valid!

For the most part - we are just missing a <title>

other more complex forms (two-factor, webauthn) have some duplicate elements (and therefore HTML id).
There are some incorrect input parameters as well (one time codes).

[ademaro]

I'm really into semantics in markup, I can take to work to get some quality work done this weekend if you don't mind...

[jwag956]

I am well down the path on this - I am using the W3C validator: https://github.com/validator/validator/wiki/Service-%C2%BB-HTTP-interface
and passing each (rendered) template to it.

Let me finish that up and I'll set you as a reviewer and we can go from there.

thanks!

[jwag956]

@ademaro if you can - please review #1065 - I will commit tomorrow - however we can always improve things with another PR
thanks.