message: equihash: Crate documentation
diff: @@ -108,6 +108,7 @@ impl Node {
  }
  }
  +/// An Equihash solution failed to verify.
  #[derive(Debug)]
  pub struct Error(Kind);
  @@ -329,6 +330,8 @@ fn is_valid_solution_recursive(
  }
  }
  +/// Checks whether `soln` is a valid solution for `(input, nonce)` with the
  +/// parameters `(n, k)`.
  pub fn is_valid_solution(
  n: u32,
  k: u32,
  