words: add more from balancer branch

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

.words

@@ -10,6 +10,7 @@ RPC
 RPCs
 
 WithRequireLeader
+InfoLevel
 args
 backoff
 blackhole
@@ -20,6 +21,7 @@ cluster_proxy
 defragment
 defragmenting
 deleter
+dev
 errClientDisconnected
 etcd
 gRPC
@@ -94,4 +96,4 @@ ServerStreams
 BidiStreams
 transientFailure
 BackoffFunc
-CallOptions
+CallOptions