add type coverage

Author: TomasVotruba

composer.json

@@ -20,7 +20,8 @@
         "rector/rector": "^0.17.1",
         "symplify/easy-ci": "^11.2",
         "symplify/phpstan-extensions": "^11.2",
-        "tomasvotruba/unused-public": "^0.1.12"
+        "tomasvotruba/unused-public": "^0.1.12",
+        "tomasvotruba/type-coverage": "^0.2.0"
     },
     "autoload": {
         "psr-4": {