update readme examples

Author: humbletim

README.md

@@ -29,3 +29,24 @@ with:
 ```
 
 NOTE: currently this aciton only supports windows and linux (if someone needs mac please let me know)
+
+NOTE 2: not all Vulkan SDK releases are available for all platforms -- if you need to differentiate by platform the recommended approach is use separate jobs (which can then have separate `vulkan-version`s). However, it is also possible to specify os-specific SDK versions by adding (`-linux`|`-windows`) suffix to the version key:
+```yaml
+  setup-both-with-versions:
+    strategy:
+      matrix:
+        runs-on: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.runs-on }}
+    steps:
+      - uses: actions/checkout@v2
+      - uses: humbletim/setup-vulkan-sdk@v1
+        with:
+          vulkan-version-linux: 1.2.154.0
+          vulkan-version-windows: 1.2.154.1
+      - name: Test Vulkan SDK Install
+        shell: bash
+        run: |
+          echo "Vulkan SDK downloaded from '$VULKAN_SDK_URL'"
+          echo "Vulkan SDK parsed app_version '$VULKAN_SDK_VERSION'"
+          test -n "$VULKAN_SDK_VERSION"
+```