feat(migrate): add README

Author: sarmstead

utils/migrate/README.md

@@ -0,0 +1,12 @@
+# Ruby Central Ghost Migrator
+
+The purpose of this package is to copy data from a staging Ghost environment to a production Ghost environment.
+
+## Setup
+
+1. The migration script reads the `slugs` key from `./config/settings.json` to round up a list of posts to port over to production. Make sure that array is up to date for your needs.
+1. Create a `.env` file using the `.env.example` file as a guide. You will need to follow [Ghost's integration instructions](https://ghost.org/docs/admin-api/) to retrieve your API keys.
+
+## How to run a migration
+
+In this directory, run the command `npm run migrate`. Then verify that the production site has the pages you expect.