CH04: Drop section about hex to base58check

This is extraneous information.  Any programmer who understands how to
create a base58check address can convert to it, or from it, using any
byte encoding supported by their programming language or one of its
libraries.

ch04.asciidoc

@@ -874,32 +874,6 @@ wrapper
 }
 ----
 
-===== Encode from hex to Base58Check
-
-To encode into Base58Check (the opposite of the previous command), we
-use the +base58check-encode+ command from Bitcoin Explorer (see
-<<appdx_bx>>) and provide the hex private key, followed by the WIF
-version prefix 128:
-
-----
-bx base58check-encode 1e99423a4ed27608a15a2616a2b0e9e52ced330ac530edcc32c8ffc6a526aedd --version 128
-5J3mBbAH58CpQ3Y5RNJpUKPE62SQ5tfcvU2JpbnkeyhfsYB1Jcn
-----
-
-===== Encode from hex (compressed key) to Base58Check
-
-To encode into Base58Check as a "compressed" private key (see
-<<comp_priv>>), we append the suffix +01+ to the hex key and then encode
-as in the preceding section:
-
-----
-$ bx base58check-encode 1e99423a4ed27608a15a2616a2b0e9e52ced330ac530edcc32c8ffc6a526aedd01 --version 128
-KxFC1jmwwCoACiCAWZ3eXa96mBM6tb3TYzGmf6YwgdGWZgawvrtJ
-----
-
-The resulting WIF-compressed format starts with a "K." This denotes that
-the private key within has a suffix of "01" and will be used to produce
-compressed public keys only (see <<comp_pub>>).
 
 ===== Public key formats