documentation

Pull request #854: feature/DEV-2339-6.4-D: Created a new quick reference guide "Monitor MySQL with Zabbix agent 2".

Merge in WEB/documentation from feature/DEV-2339-6.4-D to release/6.4

* commit '5b757742412e15f4a22383648416c5505f9cfa9b':
  [DEV-2339] Grammatical, wording, etc. improvements
  [DEV-2339] Made the guide about agent2; made agent and odbc as "other approaches"
  [DEV-2339] Grammatical, wording, etc. improvements
  [DEV-2339] Incorporated the instructions for monitoring MySQL with ODBC
  [DEV-2339] Incorporated the instructions for monitoring MySQL with Zabbix agent 2
  [DEV-2339] Updated host name and images with it; removed the use of 1st person; minor re-wording
  [DEV-2339] Finalized the newly created quick reference guide "Monitor MySQL with Zabbix agent"
  [DEV-2339] Improved the newly created quick reference guide "Monitor MySQL with Zabbix agent"
  [DEV-2339] Created new quick reference guide "Monitor MySQL with Zabbix agent"