added tests for parsing ModdedInstance

tests/root_config_test.rs

@@ -46,6 +46,11 @@ fn parse_complex() {
     assert!(
         config
             .mod_by_id("mod1")
-            .is_some_and(|e| e.path().ends_with("mods/mod1"))
+            .is_some_and(|e| e.path() == "/home/user/mods/mod1")
+    );
+    assert!(
+        config
+            .mod_by_id("mod2")
+            .is_some_and(|e| e.path().ends_with("mod2"))
     );
 }