Document using secret for encryption key

README.md

@@ -167,9 +167,10 @@ in the project directory, at `<project-dir>/.gradle/configuration-cache`. Due to
 secrets](https://docs.gradle.org/release-nightly/userguide/configuration_cache.html#config_cache:secrets), and this data needs to be encrypted in order to be safely stored in the GitHub Actions cache.
 
 In order to benefit from configuration caching in your GitHub Actions workflow, you must:
-- Enable the configuration cache for your build
 - Execute your build with Gradle 8.6 or newer. This can be achieved directly, or via the Gradle Wrapper.
-- Provide a [valid Gradle encryption key](https://docs.gradle.org/release-nightly/userguide/configuration_cache.html#config_cache:secrets:configuring_encryption_key) via the `cache-encryption-key` action parameter
+- Enable the configuration cache for your build.
+- Generate a [valid Gradle encryption key](https://docs.gradle.org/release-nightly/userguide/configuration_cache.html#config_cache:secrets:configuring_encryption_key) and save it as a [GitHub Actions secret](https://docs.github.com/en/actions/security-guides/using-secrets-in-github-actions).
+- Provide the secret key via the `cache-encryption-key` action parameter.
 
 ```yaml
 jobs:
@@ -180,7 +181,7 @@ jobs:
     - uses: gradle/gradle-build-action@v3
       with:
         gradle-version: 8.6
-        cache-encryption-key: Da25KUVSE5jbGds2zXmfXw==
+        cache-encryption-key: ${{ secrets.GradleEncryptionKey }}
     - run: gradle build --configuration-cache
 ```