Add docs about functional-language alternatives

[grantjenks]

Functional language alternatives:

• http://coconut-lang.org/
• http://docs.hylang.org/en/stable/

[refi64]

Hy doesn't have pattern matching as part of the core language.

[grantjenks]

Thanks @kirbyfan64. Good to know.

I'll probably still mention hy because it's lispy and there's a frequent association between lisp and pattern matching.

Out of curiosity, how did you find this issue so quickly?

[refi64]

I'm currently watching this repo 😁