Try focus the example crates on having useful snippets

Currently many of the example crates are working CLIs. I doubt however that anyone will ever actually run these CLIs.

The downside of them being CLIs is that they are over 50% just boilerplate for the CLIs.

What I think most developers are looking for are copyable snippets on how to do things themselves.

Imagine a new user that never used BDK and he wants a wallet with bitcoind, try figure out what pieces of code you have to copy from https://github.com/bitcoindevkit/bdk/blob/master/example-crates/example_bitcoind_rpc_polling/src/main.rs and which you don't need? It's not easy :sweat_smile: