doc: add basic readme

Author: khubo

README.md

@@ -1,2 +1,65 @@
 # express-graphql-proxy
-a proxy server built on top of express.js for graphql services.
+
+A graphql proxy server implemented on top of express for adding custom RBAC to existing graphql endpoints.
+
+```js
+import createApp from '@antstackio/express-graphql-proxy'
+
+const requestParams = {
+	resourceUri: "https://graphql-pokemon2.vercel.app",
+  headers
+};
+
+const app = createApp(
+	requestParams,
+	handlerFunc
+);
+
+const handlers = {
+	query: {
+		pokemons
+	}
+};
+
+function pokemons(variables, selectionFields, {req, res}) {
+	if(parseInt(variables.id) > 150) {
+		return res.status(400).send("cant query pokemons > 150 in this league"); 
+	}
+	return true;
+}
+
+function HandlerFunc() {
+
+  const result = gqlObject.queryObjects.every((item) =>
+    // map the gqlObject to a suitable handler
+    handlers[gqlObject.type][item.operationName](
+      item.variables,
+      item.selectedFields,
+      context
+    )
+  );
+  return result;
+}
+```
+
+## Installation
+
+This is a `node.js` module available through npm registry. Installation can be done using npm or yarn.
+
+```bash
+$ npm install @antstackio/express-graphql-proxy
+
+$ yarn add @antstackio/express-graphql-proxy
+```
+
+## Philosophy
+
+There are services that provide graphql endpoints over http leaving the developer to come up with their own mechanism for authorisation and controllings permission for the  access of resources. This library help in bootstrapping a middleware proxy server that makes it easy to implement RBAC without loosing the fun in using graphql from the client.
+
+## Documentation
+
+TODO
+
+## Examples
+
+check out the example folder for quick start.