3451d1c12e4271b6067ff246d095eb9fb1ca3bd5 Fix docs.rs features (Alekos Filini)
Pull request description:
### Description
Fix docs.rs features
### 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:
* [ ] I've added tests for the new feature
* [ ] I've added docs for the new feature
* [ ] I've updated `CHANGELOG.md`
ACKs for top commit:
danielabrozzoni:
utACK 3451d1c12e4271b6067ff246d095eb9fb1ca3bd5
notmandatory:
ACK 3451d1c12e4271b6067ff246d095eb9fb1ca3bd5
Tree-SHA512: 96dc4f816b21cf20fc2828dcfd56865f3f9add8e4aa643205879c810d09e6f2e73d6643061bf3ca98145b37e726907dedd31a145f92d6646c172a43ae2285aa8