Merge #253: Remove book (moved to simplicity-lang-org)

8328174 Remove book (moved to simplicity-lang-org) (Seth Schoen)

Pull request description:

  Equivalent to prior PR #141 which is still relevant to avoid duplication here.

ACKs for top commit:
  delta1:
    ACK 8328174
  KyrylR:
    ACK 8328174

Tree-SHA512: 1ebd7b3ce5b62fb642c011bc887aa541075b78f157a8664a50a7aab75c1535ded2a2bb96e2b3994b8bf23efe6b23f36bdde430061f32ec8e94662e5d6e175347

Author: KyrylR