Set output cache-hit to indicate if cache was hit (#275)

dist/setup/index.js

@@ -18662,9 +18662,11 @@ function restore(id) {
         ]);
         if (matchedKey) {
             core.saveState(CACHE_MATCHED_KEY, matchedKey);
+            core.setOutput('cache-hit', matchedKey === primaryKey);
             core.info(`Cache restored from key: ${matchedKey}`);
         }
         else {
+            core.setOutput('cache-hit', false);
             core.info(`${packageManager.id} cache is not found`);
         }
     });