docs(roles/apache_httpd): rewrite README from tables to structured bullet format

Replace markdown tables with a text+bullet layout for better
maintainability. Fix CRS default version (4.4.0 -> 4.24.1), prefork
variable names (spare_threads -> spare_servers), and clarify IfModule
usage policy. Add platform-specific section, wsgi example, and
document localhost endpoints.

Author: markuslf