[DOCS] Minor copy edits and typo fixes
[DOCS] Minor copy edits and typo fixes

Change-Id: I353a7917eb770aa40696476a587d7600289c336c
Cherry-picks: not for 2.x.
Reviewed-on: http://gerrit.cloudera.org:8080/10276
Reviewed-by: Alex Rodoni <b46da68bf9b818cec7052f7cdfe9b3e69485676b@cloudera.com>
Tested-by: Alex Rodoni <b46da68bf9b818cec7052f7cdfe9b3e69485676b@cloudera.com>

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