fix: remove output file if exists directly in the script

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

@@ -178,6 +178,8 @@ def systems(
     with open(pfam, "r") as pf:
         pfam_df = pd.read_csv(pf, index_col="AC", keep_default_na=False)
         systems = []
+        if (output.exists()):
+            output.unlink()
         with open(output, "a") as ty:
             for file in dir.iterdir():
                 if file.suffix == ".md":