Update README.md

Updated with instruction and screenshot

Author: Leo Chen

README.md

@@ -1,2 +1,33 @@
 # harmony-arm
-Harmony On ARM64
+Harmony On ARM64. It was tested on c6g instance on AWS.
+
+## Quickstart
+* launch m6g/c6g instance; ssh into the instance
+* install build tools
+```bash
+sudo yum install glibc-static gmp-devel gmp-static openssl-libs openssl-static gcc-c++
+```
+* download harmony git repos
+```bash
+mkdir -p $(go env GOPATH)/src/github.com/ethereum
+cd $(go env GOPATH)/src/github.com/ethereum
+
+git clone https://github.com/harmony-one/go-ethereum.git
+
+mkdir -p $(go env GOPATH)/src/github.com/harmony-one
+cd $(go env GOPATH)/src/github.com/harmony-one
+
+git clone https://github.com/harmony-one/mcl.git
+git clone https://github.com/harmony-one/bls.git
+git clone https://github.com/harmony-one/harmony.git
+
+cd harmony
+make arm_static
+```
+
+## Screenshot
+![screenshot](screencast/harmony-on-arm-480.gif)
+
+
+## Links
+[Medium Post](https://medium.com/@leo_hao/harmony-on-arm64-d4508de9929f)