ZOOKEEPER-3210: typo in zookeeperInternals doc

Author: Stanislav Knot <sknot@redhat.com>

Reviewers: fangmin@apache.org, andor@apache.org

Closes #732 from stanlyDoge/patch-1

zookeeper-docs/src/main/resources/markdown/zookeeperInternals.md

@@ -185,7 +185,7 @@ to the leader, the leader will tell the follower to discard U.
 
 A new leader establishes a zxid to start using for new proposals by getting the
 epoch, e, of the highest zxid it has seen and setting the next zxid to use to be
-(e+1, 0), fter the leader syncs with a follower, it will propose a NEW_LEADER
+(e+1, 0), after the leader syncs with a follower, it will propose a NEW_LEADER
 proposal. Once the NEW_LEADER proposal has been committed, the leader will activate
 and start receiving and issuing proposals.