c4d5f2ccd8435b9c424eec5ba35ba44a3383b04d doc(example_cli): add missing cli docs (vmammal)
Pull request description:
### 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
ACKs for top commit:
evanlinjin:
ACK
c4d5f2ccd8435b9c424eec5ba35ba44a3383b04d
Tree-SHA512: 43684abbb32570f07e0dc05ed07062bc7969cbe7c4fefe8ae7ebe41ac28aedfbba76ffc801bc4ddb3bf08a940ca81c128376dc3f6c76a04f1391e43c18e0d50b