Clean out Deprecated Items from docs

[Caleb-o]

There are items listed under the standard lib ref card section that have been deprecated in code. On Discord, Lerno said that these can probably just be removed completely. Some items under std lib might also be deprecated, but will need review to see if that's the case.

Items I've noted as deprecated so far:

• std::collections::triple
• std::collections::tuple
• std::core::types::is_equatable_value(value)
• std::core::types::is_comparable_value(value)

A search for @deprecated in lib/std shows 27 results over 10 files