Merge #749: docs: update it to use CMake for Bitcoin Core

a41fe6f docs: update it to use CMake for Bitcoin Core (Bruno Garcia)

Pull request description:

ACKs for top commit:
  achow101:
    ACK a41fe6f

Tree-SHA512: deba536235216b08e28f50198df8c8bff710d9567d68ec30d49bdc2240862b831c61f2cab4f5f476b8c682954d55ef187153e4f75c47154d900b10c7d62c00b0

docs/examples/bitcoin-core-usage.rst

@@ -30,10 +30,9 @@ Clone Bitcoin Core and build it. Clone HWI.
 
     $ git clone https://github.com/bitcoin/bitcoin.git
     $ cd bitcoin
-    $ ./autogen.sh
-    $ ./configure
-    $ make
-    $ src/bitcoind -daemon -addresstype=bech32 -changetype=bech32
+    $ cmake -B build
+    $ cmake --build build
+    $ build/src/bitcoind -daemon -addresstype=bech32 -changetype=bech32
     $ cd ..
     $ git clone https://github.com/bitcoin-core/HWI.git
     $ cd HWI