fix README typo

README.md

@@ -2,10 +2,14 @@ Pika
 ====
 
 Pika is redis like database.
+
 Pika used Nemo as storage engine, Nemo is developed base on rocksdb.
+
 Nemo support multi data structure by using rocksdb's kv port. Such as list,
 hash, zst
+
 Because rocksdb is using disk, so Nemo don't have capacity limitation.
+
 The protocol used to contact with Pika is redis protocol, so you don't need to
 change your code to migrate to Pika