Update nano config for adoc files

en/books/fdp-primer/book/#editor-config-nano

section still refers to the old xml syntax. This patch updates the
config to support adoc documents. Additionally:

• The syntax highlight is collected from different locations in the web
• Remove line-wrapping related stuffs as in ASCIIDOC we can have longer lines as there is a rule "one sentence per line".

PR: 264899
Obtained from: crees