Update landing page content

Summary: Changes based on comments in D62985

Test Plan:
Visual

https://www.facebook.com/pxlcld/pvVs

Reviewers: lgalanis, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63477

docs/_data/features.yml

@@ -1,19 +1,19 @@
-- title: Optimized for Fast Storage
-  text: |
-        RocksDB is optimized for fast, low latency storage such as flash drives. RocksDB exploits the full potential of high read/write rates offered by flash or RAM.
-  image: images/promo-flash.svg
-
 - title: High Performance
   text: |
         RocksDB uses a log structured database engine, written entirely in C++, for maximum performance. Keys and values are just arbitrarily-sized byte streams.
   image: images/promo-performance.svg
 
+- title: Optimized for Fast Storage
+  text: |
+        RocksDB is optimized for fast, low latency storage such as flash drives and high-speed disk drives. RocksDB exploits the full potential of high read/write rates offered by flash or RAM.
+  image: images/promo-flash.svg
+
 - title: Adaptable
   text: |
-        RocksDB can also be used as a storage engine for databases. [MongoRocks](https://github.com/mongodb-partners/mongo-rocks) and [MyRocks](https://github.com/facebook/mysql-5.6) are two production examples.
+        RocksDB is adaptable to different workloads. From database storage engines such as [MyRocks](https://github.com/facebook/mysql-5.6) to [application data caching](http://techblog.netflix.com/2016/05/application-data-caching-using-ssds.html) to embedded workloads, RocksDB can be used for a variety of data needs.
   image: images/promo-adapt.svg
 
 - title: Basic and Advanced Database Operations
   text: |
-        RocksDB provides basic operations such as opening and closing a database, reading and writing to more advanced operations such as slicing and iteration.
+        RocksDB provides basic operations such as opening and closing a database, reading and writing to more advanced operations such as merging and compaction filters.
   image: images/promo-operations.svg