doc update and version bump

README.md

@@ -18,7 +18,16 @@ He also mentioned that if you want to keep several concurrent functions warm, th
 
 You can read the key takeaways from his talk [here](https://www.jeremydaly.com/15-key-takeaways-from-the-serverless-talk-at-aws-startup-day/).
 
-Following these "best practices", I created **Lambda Warmer**. It is a lightweight module that can be added to your Lambda functions to manage "warming" events as well as handling automatic fan-out for initializing *concurrent functions*. Since Lambda functions can always invoke themselves, there are *no additional permissions* to add. Just instrument your code and schedule your CloudWatch Events.
+Following these "best practices", I created **Lambda Warmer**. It is a lightweight module that can be added to your Lambda functions to manage "warming" events as well as handling automatic fan-out for initializing *concurrent functions*. Just instrument your code and schedule your CloudWatch Events.
+
+**NOTE:** Lambda Warmer will invoke the function multiple times using the AWS-SDK in order to scale concurrency (if you want to). Your functions MUST have `lambda:InvokeFunction` permissions so that they can invoke themselves. Following the Principle of Least Privilege, you should limit the `Resource` to the function itself, e.g.:
+
+```yaml
+- Effect: "Allow"
+  Action:
+    - "lambda:InvokeFunction"
+  Resource: "arn:aws:lambda:us-east-1:{AWS-ACCOUNT-ID}:function:my-test-function"
+```
 
 ## Installation
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lambda-warmer",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Keep your Lambda functions warm",
   "main": "index.js",
   "scripts": {