Hide instructions in README for now

Author: tcbyrd

README.md

@@ -1,5 +1,10 @@
 ## Lambda Handler for Probot
 
+
+
+<details>
+<summary>TODO: Not published yet. Coming soon.</summary>
+
 ```shell
 $ npm install @probot/serverless-lambda
 ```
@@ -10,3 +15,5 @@ const serverless = require('@probot/serverless-aws');
 // run the app defined in index.js
 module.exports = serverless('.')
 ```
+
+</details>