update readme

README.md

@@ -69,13 +69,18 @@ This tells Gradle where to search for plugins. The plugins in this repository ar
 
 Your credentials to the GitHub Packages repository need to be defined in your local `gradle.properties` file, which you can find in your home directory, e.g. `~/.gradle/gradle.properties`.
 
-Please add the following parameters:
+Before doing this, ensure you have [created a personal access token](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens#creating-a-personal-access-token-classic)
+in GitHub and configured it with `repo`, `write:packages` and `read:packages` access. The token must also be [authorized with (MoJ) SSO](https://docs.github.com/en/enterprise-cloud@latest/authentication/authenticating-with-saml-single-sign-on/authorizing-a-personal-access-token-for-use-with-saml-single-sign-on).
+
+Once you have your personal access token, please add the following parameters to `~/.gradle/gradle.properties`:
 
 ```yaml
 project.ext.gitPackageUser = <your GitHub username>
 project.ext.gitPackageKey = <your GitHub access token>
 ```
 
+Do not include `'` or `"` around your username or token as these are treated literally as part of the value by gradle.
+
 ### Applying the Plugin
 
 In your (root) `build.gradle`, add the plugin dependency via the Gradle Plugin DSL, e.g: