Adding 'bets#show' content

This PR adds content for the 'bets#show' view page.

This PR does NOT address styling of the page. That will be separate.

cc @Clee681 @irmiller22 LMK what you think please
@irmiller22 I think `button_to` generates a `<form>` tag, which may not be what we want but I could be wrong.