add workspaces input field to support non-root projects

action.yml

@@ -25,6 +25,9 @@ inputs:
     description: "Automatically configure Rust cache"
     required: false
     default: "true"
+  cache-workspaces:
+    description: "Paths to multiple Cargo workspaces and their target directories, separated by newlines."
+    required: false
   matcher:
     description: "Enable the Rust problem matcher"
     required: false
@@ -171,3 +174,5 @@ runs:
     - name: Setup Rust Caching
       if: inputs.cache == 'true'
       uses: Swatinem/rust-cache@v2
+      with:
+        workspaces: ${{inputs.cache-workspaces}}