[DOCS] Updates to the load balancing algorithms section
[DOCS] Updates to the load balancing algorithms section

Further refined the Load Balancing Algorithm section
with reviews and comments from SME.

Change-Id: Ia697aafc799b2a3414a208aa85e1de4bf0214317
Reviewed-on: http://gerrit.cloudera.org:8080/9869
Reviewed-by: Tim Armstrong <2f8e34250f03a653da3dc27f7ec203eafdde80fc@cloudera.com>
Tested-by: Impala Public Jenkins

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala