docs: add installation instructions

README.md

@@ -1,6 +1,10 @@
 # SubQL
 SubQL enables real time data subscriptions to GraphQL APIs. 
 
+## Installation
+1. Fork from <https://github.com/CMDco/subql>
+2. ```npm install```
+
 ## Disclaimer
 The SubQL is in alpha. Every feature should be considered experimental and has the possibility of breaking or being removed in the future. If you have any questions, comments, suggestions for features, or any other concerns please contact [Martin-Ting](https://github.com/martin-ting). Our team (listed below) is very open to suggestions and feedback and encourage it if you try our library out. We hope to provide a great tool for graphQL developers to bring real time data to their APIs.