docs: Update gateway doc with roadmap section. (#3918)

docs/gateway/README.md

@@ -1,13 +1,8 @@
 # Minio Gateway [![Slack](https://slack.minio.io/slack?type=svg)](https://slack.minio.io)
+Minio Gateway adds Amazon S3 compatibility to third party cloud storage providers. Currently only Microsoft Azure Blob Storage is supported. 
 
-Minio gateway adds Amazon S3 compatibility to third party cloud storage providers. Supported providers are:
+## Run Minio Gateway for Microsoft Azure Blob Storage
-
-- Azure Blob Storage
-
-## Run Minio Gateway for Azure Blob Storage
-
 ### Using Docker
-
 ```
 docker run -p 9000:9000 --name azure-s3 \
  -e "MINIO_ACCESS_KEY=azureaccountname" \
@@ -16,7 +11,6 @@ docker run -p 9000:9000 --name azure-s3 \
 ```
 
 ### Using Binary
-
 ```
 export MINIO_ACCESS_KEY=azureaccountname
 export MINIO_SECRET_KEY=azureaccountkey
@@ -27,13 +21,11 @@ minio gateway azure
 `mc` provides a modern alternative to UNIX commands such as ls, cat, cp, mirror, diff etc. It supports filesystems and Amazon S3 compatible cloud storage services.
 
 ### Configure `mc`
-
 ```
 mc config host add myazure http://gateway-ip:9000 azureaccountname azureaccountkey
 ```
 
-### List containers on Azure
+### List containers on Microsoft Azure
-
 ```
 mc ls myazure
 [2017-02-22 01:50:43 PST]     0B ferenginar/
@@ -41,6 +33,11 @@ mc ls myazure
 [2017-02-26 22:10:11 PST]     0B test-container1/
 ```
 
+## Roadmap
+* Minio & AWS S3
+* Edge Caching - Disk based proxy caching support
+* Google Cloud Storage 
+
 ## Explore Further
 - [`mc` command-line interface](https://docs.minio.io/docs/minio-client-quickstart-guide)
 - [`aws` command-line interface](https://docs.minio.io/docs/aws-cli-with-minio)