Add SBT in cache managers. (#302)

README.md

@@ -69,6 +69,7 @@ Currently, the following distributions are supported:
 The action has a built-in functionality for caching and restoring dependencies. It uses [actions/cache](https://github.com/actions/cache) under hood for caching dependencies but requires less configuration settings. Supported package managers are gradle and maven. The format of the used cache key is `setup-java-${{ platform }}-${{ packageManager }}-${{ fileHash }}`, where the hash is based on the following files:
 - gradle: `**/*.gradle*`, `**/gradle-wrapper.properties`
 - maven: `**/pom.xml`
+- sbt:  `**/build.sbt`
 
 The workflow output `cache-hit` is set to indicate if an exact match was found for the key [as actions/cache does](https://github.com/actions/cache/tree/main#outputs).
 
@@ -99,6 +100,19 @@ steps:
   run: mvn -B package --file pom.xml
 ```
 
+#### Caching sbt dependencies
+```yaml
+steps:
+- uses: actions/checkout@v3
+- uses: actions/setup-java@v3
+  with:
+    distribution: 'temurin'
+    java-version: '11'
+    cache: 'sbt'
+- name: Build with SBT
+  run: sbt package
+```
+
 ### Check latest
 In the basic examples above, the `check-latest` flag defaults to `false`. When set to `false`, the action tries to first resolve a version of Java from the local tool cache on the runner. If unable to find a specific version in the cache, the action will download a version of Java. Use the default or set `check-latest` to `false` if you prefer a faster more consistent setup experience that prioritizes trying to use the cached versions at the expense of newer versions sometimes being available for download.