doc: add trailing slashes in URLs

doc/python_stub.py

@@ -68,7 +68,7 @@ def print_stub_functions() -> None:
     with open(DOC_DIR / "weechat_plugin_api.en.adoc") as api_doc_file:
         api_doc = api_doc_file.read()
         for match in function_pattern.finditer(api_doc):
-            url = f'https://weechat.org/doc/api#_{match["function"]}'
+            url = f'https://weechat.org/doc/api/#_{match["function"]}'
             print(
                 f"""\n
 def {match["function"]}{match["args"]}{match["return"]}