Adding release doc

docs/docs/SUMMARY.md

@@ -69,6 +69,9 @@
 * [Compatibility API's](compatibility/compatibility.md)  
   * [Apache Storm](compatibility/storm.md)
 * [Releases](release/README.md)  
+  * [Twister2 v0.5.0](release/twister2_release_0_5_0.md)
+  * [Twister2 v0.4.0](release/twister2_release_0_4_0.md)
+  * [Twister2 v0.3.0](release/twister2_release_0_3_0.md)
   * [Twister2 v0.2.2](release/twister2_release_0_2_2.md)
   * [Twister2 v0.2.1](release/twister2_release_0_2_1.md)
   * [Twister2 v0.2.0](release/twister2_release_0_2_0.md)

docs/docs/release/twister2_release_0_5_0.md

@@ -0,0 +1,68 @@
+---
+id: 0.5.0
+title: Twister2 Release 0.5.0
+sidebar_label: Twister2 Release 0.5.0
+---
+
+
+This is a major release of Twister2. 
+
+You can download source code from [Github](https://github.com/DSC-SPIDAL/twister2/releases)
+
+## Features of this release
+
+1. Support for UCX 
+2. Performance improvements of shuffle operations
+3. Hash Join implementation
+4. Windowing support for TSet API
+5. CSV data readers
+
+## Minor features
+
+Apart from these, we have done many code improvements and bug fixes.
+
+## Next Release
+
+In the next release we are working to improve the Fault tolerance, fix issues and integrate with AI
+systems.
+
+## Components in Twister2
+
+We support the following components in Twister2
+
+1. Resource provisioning component to bring up and manage parallel workers in cluster environments
+    1. Standalone
+    2. Kubernetes
+    3. Mesos
+    4. Slurm 
+    5. Nomad
+2. Parallel and Distributed Operators in HPC and Cloud Environments
+    1. Twister2:Net - a data level dataflow operator library for streaming and large scale batch analysis
+    2. Harp - a BSP (Bulk Synchronous Processing) innovative collective framework for parallel applications and machine learning at message level
+    3. OpenMPI (HPC Environments only) at message level
+3. Task System
+    1. Task Graph 
+       * Create dataflow graphs for streaming and batch analysis including iterative computations 
+    2. Task Scheduler - Schedule the task graph into cluster resources supporting different scheduling algorithms
+       * Datalocality Scheduling
+       * Roundrobin scheduling
+       * First fit scheduling
+    3. Executor - Execution of task graph     
+       * Batch executor
+       * Streaming executor
+4. TSet for distributed data representation (Similar to Spark RDD, Flink DataSet and Heron Streamlet)
+    1. Iterative computations
+    2. Data caching
+5. APIs for streaming and batch applications
+    1. Operator API
+    2. Task Graph based API
+    3. TSet API
+6. Support for storage systems
+    1. HDFS
+    2. Local file systems
+    3. NFS for persistent storage
+7. Web UI for monitoring Twister2 Jobs
+8. Apache Storm Compatibility API
+9. Apache BEAM API
+10. Connected DataFlow (Experimental)
+    1. Supports creation of multiple dataflow graphs executing in a single job