Exclude removed contributing guide from repo_helper

Author: domdfcoding

repo_helper.yml

@@ -14,7 +14,6 @@ min_coverage: 100
 use_whey: true
 enable_conda: False
 sphinx_html_theme: furo
-standalone_contrib_guide: true
 docs_fail_on_warning: true
 
 python_versions:
@@ -43,3 +42,6 @@ classifiers:
 
 keywords:
  - tox
+
+exclude_files:
+ - contributing