Resolve "front-matter linter"

Closes #320 (closed)

packages/df-wiki-cli/df_wiki_cli/content/main.py

@@ -62,4 +62,6 @@ def lint(
             # print(exc.errors())
             for err in exc.errors():
                 print(f"{err['msg']} : {err['type']} {err['loc']}")
-        
+            print("\n")
+        else:
+            print("OK!\n")