Store sass in a "$rootProject/.gradle/sass" subdirectory per subproje…

…ct (#23)

src/main/java/io/miret/etienne/gradle/sass/SassGradlePluginExtension.java

@@ -5,6 +5,7 @@
 import org.gradle.api.Project;
 
 import java.io.File;
+import java.nio.file.Path;
 
 @Getter
 @Setter
@@ -19,10 +20,14 @@ public class SassGradlePluginExtension {
   private boolean autoCopy;
 
   public SassGradlePluginExtension (Project project) {
+    Path projectPath = project.getRootDir()
+        .toPath()
+        .relativize(project.getProjectDir().toPath());
     this.version = "1.54.0";
-    this.directory = project.getProjectDir ()
+    this.directory = project.getRootDir()
         .toPath ()
         .resolve (".gradle/sass")
+        .resolve(projectPath)
         .toFile ();
     this.baseUrl = "https://github.com/sass/dart-sass/releases/download";
     this.autoCopy = true;