docs: update the prettify.js files with new directives

docs: update the prettify.js files with new directives

Procedure that I've used:

1) Copy https://httpd.apache.org/docs/2.4/mod/directives.html
   to a text file.
2) Generate a csv with something like
   cat /tmp/trunk_directives | sort | tr "\n" ","
3) Replace the content of CONFIG_KEYWORDS in prettify.js
   with the list generated in 2)
4) Run the command the MINIFY command to generate prettify.min.js

This change should bring out highlight up to speed with the
recent docs (like mod_md's).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1821119 13f79535-47bb-0310-9956-ffa450edef68