18e8da3937 docs: Add doctest for Anchor implementation on BlockId (Vladimir Fomene)
480c2730de feat: Implement Anchor for BlockId (Vladimir Fomene)
Pull request description:
### Description
This PR fixes#1062.
It implements the `Anchor` trait on `BlockId`.
### Checklists
#### All Submissions:
* [x] I've signed all my commits
* [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
* [x] I ran `cargo fmt` and `cargo clippy` before committing
#### New Features:
* [x] I've added tests for the new feature
* [x] I've added docs for the new feature
ACKs for top commit:
evanlinjin:
ACK 18e8da3937
Tree-SHA512: af9da8b4e9c7f2a110340efa4e4c86d9b96ea1275f0a66f08e26a47fcacd89e318a32c845e2a4302f3332eeb4c6a976c3771b1d9881adf4feda90d6ba1a2dd9d
e5fb1ec7ff