Update cluster.asciidoc - fix invalid asciidoc

docs/reference/modules/cluster.asciidoc

@@ -43,12 +43,10 @@ kinds of shard to be allocated.
 --
 Can be set to:
 
-[horizontal]
-
-`all`:: (default) Allows shard allocation for all kinds of shards.
-`primaries`::  Allows shard allocation only for primary shards.
-`new_primaries`:: Allows shard allocation only for primary shards for new indices.
-`none`::No shard allocations of any kind are allowed for all indices.
+* `all` - (default) Allows shard allocation for all kinds of shards.
+* `primaries` -  Allows shard allocation only for primary shards.
+* `new_primaries` - Allows shard allocation only for primary shards for new indices.
+* `none` - No shard allocations of any kind are allowed for all indices.
 --
 
 `cluster.routing.rebalance.enable`::
@@ -59,10 +57,10 @@ kinds of shard to be rebalanced.
 --
 Can be set to:
 
-`all`:: (default) Allows shard balancing for all kinds of shards.
-`primaries`:: Allows shard balancing only for primary shards.
-`replicas`:: Allows shard balancing only for replica shards.
-`none`:: No shard balancing of any kind are allowed for all indices.
+* `all` - (default) Allows shard balancing for all kinds of shards.
+* `primaries` - Allows shard balancing only for primary shards.
+* `replicas` - Allows shard balancing only for replica shards.
+* `none` - No shard balancing of any kind are allowed for all indices.
 --
 
 `cluster.routing.allocation.same_shard.host`::