Change alphanet -> testnet; add super basic readme

Author: SarahFowler73

README.md

@@ -1,2 +1,7 @@
 # node-cloudformation
-Cloudformation scripts for deploying public nodes on AWS
+CloudFormation scripts for use along with [node-docker repo](https://github.com/tqtezos/node-docker) and [tezos-updater repo](https://github.com/tqtezos/tezos-updater) to be used for deploying public nodes on AWS.
+
+1. Fork all repositories. 
+2. Update CloudFormation scripts for tezos-updater and frontnode-standalone to point to your github account (instead of tqtezos) and change testnet to the appropriate branch you want to deploy if you'd like to deploy a mainnet or zeronet node. 
+3. Follow steps on aws console CloudFormation to deploy in order: VPCs, tezos-updater, frontnode-standalone. 
+

frontnode-standalone.yaml

@@ -51,7 +51,7 @@
 
     NodeGitHubBranch:
       Type: String
-      Default: alphanet
+      Default: testnet
       Description: The branch of the node repo to continuously deploy.
 
     GitHubToken:

tezos-updater.yaml

@@ -21,7 +21,7 @@ Parameters:
 
   GitHubBranch:
     Type: String
-    Default: alphanet
+    Default: testnet
     Description: The branch of the repo to continuously deploy.
 
   GitHubToken: