chore: update readme

README.md

@@ -62,7 +62,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Evaluate vote
-        uses: myyk/git-democracy@v1
+        uses: myyk/git-democracy@v2
 ```
 
 The name of the workflow must be `Voting` to match the badge that will be
@@ -127,3 +127,13 @@ jienormous: 1
 ## Sample Project
 
 An example of a fully wired up project: https://github.com/myyk/git-democracy-example
+
+# Migration from v1 to v2 guide
+
+Please do not use `v1` tag as it is not secure since a pull requester could overwrite your `.voters.yml` and `.voting.yml` files.
+
+Easy upgrade steps:
+
+1. Move your `.voters.yml` and `.voting.yml` files into your `.github/workflows/` directory somewhere.
+1. Make sure all your voters are also Pull Requesters in your repo/org/account settings.
+1. Update `uses: myyk/git-democracy@v1` -> `uses: myyk/git-democracy@v2`