Change input mode for sign-in form

[MIfoodie]

-Added the inputmode of "email" to tell mobile browsers to change to the email keyboard for username/email input

-Added the inputmode of "numeric" to tell mobile browsers to change to the numeric keyboard for 2fa input (https://www.w3schools.com/TAgs/att_inputmode.asp)

-Changed two-factor code input type to "numeric" to provide a greater hint to autofill that this is where they should fill in 2fa codes

This is my first PR in this repo so let me know if I did something horribly wrong or taboo :)

[IMB11]

The inputmode additions are good!

However, changing from type="text" to type="number" for the 2fa input changes the way the value is parsed when a authenticator app or autofill extension pastes into the field;

• A code like 012345 becomes 12345, breaking validation
• Users can enter ., -, e (scientific notation) depending on browser/mobile keyboard being used (gboard allows this)
• Spinner controls will appear (not entirely sure if you have disabled these?) - the increment/decrement arrows are useless and add visual noise
• Breaks the maxlength attribute, maxlength doesn't work on type="number"

I would recommend you revert the type changes, and keep the inputmode ones - MDN is also a bit more authoritative than w3 asw for future reference :) https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes/autocomplete

[MIfoodie]

@IMB11 Thank you for the review! 169e502 should fix it. I didn't realize that the number type did more than just make the box only accept numbers.