Updates to Snort guides for CentOS, rule writing in 3

Our documentation on Snort 3 running on CentOS and the Snort Rules Writing guide to Snort 3.
Thanks to community member Yaser for providing the updates.
The Snort 3 guide now has expanded information on logging options — such as syslog and JSON. There is also a new performance optimization section.
The Rules Writing guide has new syntax comparisons for various file_type detection for various Snort versions, as well as a comparison of app ID.
As always, you can view all of our guides on the Snort Documentation page.