Update outdated summary, instructions, etc. pages

[HofiOne]

• https://syslog-ng.github.io/admin-guide/010_Introduction_to_syslog-ng/000_What_syslog-ng_is
• https://syslog-ng.github.io/admin-guide/030_Installing_syslog-ng/001_Compiling_options
• https://syslog-ng.github.io/admin-guide/030_Installing_syslog-ng/000_Compiling_syslog-ng_from_source
• Manual pages https://syslog-ng.github.io/admin-guide/190_The_syslog-ng_manual_pages/README
  • especially of the supported parameters of syslog-ng itself https://syslog-ng.github.io/admin-guide/190_The_syslog-ng_manual_pages/005_syslog-ng_manual
  • or, the tools like syslog-ng-ctl https://syslog-ng.github.io/admin-guide/190_The_syslog-ng_manual_pages/007_syslog-ng_control_tool_manual
  • etc.