Merge pull request volcano-sh#48 from volcano-sh/2019-03-27-improve-docs

Author: Klaus Ma

README.md

@@ -2,11 +2,46 @@
 
 [![Build Status](https://travis-ci.com/volcano-sh/volcano.svg?token=sstuqFE81ukmNz9cEEtd&branch=master)](https://travis-ci.com/volcano-sh/volcano) [![slack](https://img.shields.io/badge/Volcano-%23SLACK-red.svg)](https://volcano-sh.slack.com/messages/CGET876H5/) 
 
-Volcano is a Kubernetes-based system for high performance workload, providing mechanisms for applications
-which would like to run high performance workload leveraging Kubernetes, e.g. Tensorflow, Spark, MPI.
-
-Volcano builds upon a decade and a half of experience on running high performance workload workloads at scale
-using several systems, combined with best-of-breed ideas and practices from the open source community.
+Volcano is system for runnning high performance workloads on
+Kubernetes.  It provides a suite of mechanisms currently missing from
+Kubernetes that are commonly required by many classes of high
+performance workload including:
+
+1. machine learning/deep learning,
+2. bioinformatics/genomics, and 
+3. other "big data" applications.
+
+These types of applications typically run on generalized domain
+frameworks like Tensorflow, Spark, PyTorch, MPI, etc, which Volcano integrates with.
+
+Some examples of the mechanisms and features that Volcano adds to Kubernetes are:
+
+1. Job management extensions and improvements, e.g:
+    1. Multi-pod jobs
+	2. Lifecycle management extensions including suspend/resume and
+       restart.
+	3. Improved error handling
+	4. Indexed jobs
+	5. Task dependencies
+2. Scheduling extensions, e.g:
+    1. Co-scheduling
+	2. Fair-share scheduling
+	3. Queue scheduling
+	4. Preemption and reclaims
+	5. Reservartions and backfills
+	6. Topology-based scheduling
+3. Runtime extensions, e.g:
+    1. Support for specialized continer runtimes like Singularity,
+       with GPU accelerator extensions and enhanced security features.
+4. Other
+    1. Data locality awareness and intelligent scheduling
+	2. Optimizations for data throughput, round-trip latency, etc.
+	
+
+Volcano builds upon a decade and a half of experience running a wide
+variety of high performance workloads at scale using several systems
+and platforms, combined with best-of-breed ideas and practices from
+the open source community.
 
 ## Overall Architecture
 
@@ -18,38 +53,51 @@ The easiest way to use Volcano is to use the Helm chart.
 
 
 ### 1. Volcano Image
-Official images now are not available on DockerHub, however you can build them locally with command:
+
+Official images are not yet available on DockerHub, however you can
+build them locally with the command:
+
 ```
 make docker
 ``` 
+
 **NOTE**: You need ensure the images are correctly loaded in your kubernetes cluster, for
 example, if you are using [kind cluster](https://github.com/kubernetes-sigs/kind), 
 try command ```kind load docker-image <image-name>:<tag> ``` for each of the images.
 
 ### 2. Helm charts
-First of all, clone repo to your local path
+First of all, clone the repo to your local path:
+
 ```
 # mkdir -p $GOPATH/src/volcano.sh/
 # cd $GOPATH/src/volcano.sh/
 # git clone https://github.com/volcano-sh/volcano.git
 ```
-Second, install required helm plugin and generate valid certificate, volcano uses a helm plugin **gen-admission-secret**
-to generate certificate for admission service to communicate with kubernetes API server.
+
+Second, install the required helm plugin and generate valid
+certificate, volcano uses a helm plugin **gen-admission-secret** to
+generate certificate for admission service to communicate with
+kubernetes API server.
+
 ```
 #1. Install helm plugin
 helm plugin install installer/chart/volcano/plugins/gen-admission-secret
 
 #2. Generate secret within service name
 helm gen-admission-secret --service <specified-name>-admission-service --namespace <namespace>
 ```
+
 Finally, install helm chart.
+
 ```
 helm install installer/chart/volcano --namespace <namespace> --name <specified-name>
 ```
+
 **NOTE**:The ```<specified-name>``` used in the two commands above should be identical.
 
 
-To Verify your installation run the below commands
+To Verify your installation run the following commands:
+
 ```
 #1. Verify the Running Pods
 # kubectl get pods --namespace <namespace>