Merge bitcoindevkit/bdk#1791: Update bdk 0.30.x README docs to deprecate the bdk...

Merge bitcoindevkit/bdk#1791: Update bdk 0.30.x README docs to deprecate the bdk library

6d2e2431d7bccb1f34718eca0025e5a4123cb189 release: bump version to 0.30.1 (Steve Myers)
e52c91115a563c4a3c55e2e1d112e35ec3504171 docs: update README to deprecate the bdk lib (Steve Myers)

Pull request description:

  ### Description

  This is needed to direct new and existing users to upgrade to the new `bdk_wallet`1.0 library.

  I also used this PR to bump the version and changelog to v0.30.1 so we're ready to publish the fix in #1782.

  ### 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:
  thunderbiscuit:
    ACK 6d2e2431d7bccb1f34718eca0025e5a4123cb189.

Tree-SHA512: b5d5eb8ae2df719e18430a7629970f0ec06e023d07a7ff1ea03bb7fb43b5bcb27d5975473cc2c1a310afe16b64263551ce2d25c2a44a0302cfdacd9a41f597d7