Readme.md: Grammar update on the link to the KB article

Signed-off-by: Aron Lander <aron.lander@op5.com>

README.md

@@ -115,7 +115,7 @@ $ /opt/plugins/check_vmware_api --help
 ```
 
 ## Documentation
-* Read the OP5 [Monitoring VMware ESX, ESXi, vSphere and vCenter Server](https://kb.op5.com/x/J4IK)  (for OP5 Monitor)
+* Read the OP5 [Monitoring VMware ESX, ESXi, vSphere and vCenter Server](https://kb.op5.com/x/J4IK)  (for OP5 Monitor) documentation
 * Subscribe to the [op5-users](http://lists.op5.com/mailman/listinfo/op5-users) mailing list
 * Browse the [mailing list archives](http://lists.op5.com/pipermail/op5-users/)