Merge bitcoindevkit/bdk-cli#300: docs: update cargo features in README to match Cargo...

047bbbe106d485da4d7d9e6fa7e06220b3876b93 docs: update sp code key params in docs example (Vihiga Tyonum)
4a1ff1b4a52ab4b83ad7193cb67a5bebb2339d16 docs: update cargo feature flags in README to match Cargo.toml (musab1258)

Pull request description:

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  ### Description

  The README referenced outdated cargo feature flags `kyoto` and `sp`, which will cause build failures for users following the instructions. This commit updates the documentation to use the correct flags `cbf` and `silent-payments` as defined in the current `Cargo.toml`.

  Fixes #299

  ### Notes to the reviewers

  This is a documentation update to the `README.md`. I specifically left the reference to `Kyoto` in the "About" section intact, as it correctly refers to the underlying `bdk_kyoto` library/concept, and only updated the actual Cargo feature flags in the code blocks and feature lists.

  ## Changelog notice

  * Fixed outdated cargo feature flags (`kyoto` -> `cbf` and `sp` -> `silent-payments`) in the README instructions.

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk-cli/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

  #### Bugfixes:

  * [ ] This pull request breaks the existing API
  * [ ] I've added tests to reproduce the issue which are now passing
  * [x] I'm linking the issue being fixed by this PR

Top commit has no ACKs.

Tree-SHA512: 680ff0f96eab3b28585beaf4d6be89c05985edaf61369207fe2d9ac3722a9d8b69fd898885e13847117f8b5481bbf16b0642506321558f08167c2f6f554bfd12