Docs: add just example for using bdk-cli with bitcoind regtest node

[tvpeter]

Description

Fixes #199

Update README to show how to use just command runner to start, connect and fund your bdk-cli wallet with local bitcoind regtest node. Also, fixed clippy warnings.

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

[coveralls]

Pull Request Test Coverage Report for Build 15624082725

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 6 (0.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.005%) to 2.66%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/handlers.rs	0	1	0.0%
src/utils.rs	0	5	0.0%

Totals
Change from base Build 15508986518:	-0.005%
Covered Lines:	25
Relevant Lines:	940

---

💛 - Coveralls

[notmandatory]

ACK 2524da3

I pushed an additional commit, if it looks OK to you feel free to merge the PR. Thanks for getting the build warnings fixed too.

[tvpeter]

ACK 2524da3

Thank you for improving the formatting and steps.