This commit adds description about
Browbeat(https://github.com/openstack/browbeat), a tool that orchestrates
several upstream tools to monitor/performance test OpenStack Clouds
+ Dina's suggestions
Change-Id: I53e4c0691e9d63c29d9c6e6a6afb06fb9232a22d
Note: diagrams and pictures will be added in the separated commit,
due to the fact that some of the tools had new releases recently
and some documentation diagrams are not up to date now.
Change-Id: Ie69808be13e932d2c1b72ea35e8f54ff7644aa50
