Update about-custom-repository-roles.md (#38930)

Co-authored-by: Anne-Marie <102995847+am-stead@users.noreply.github.com>

content/organizations/managing-peoples-access-to-your-organization-with-roles/about-custom-repository-roles.md

@@ -106,7 +106,9 @@ For more information, see "[AUTOTITLE](/discussions)."
 - Set interaction limits
 {%- endif %}
 - Set the social preview
-- Push commits to protected branches (branch protection rules will still apply)
+- Push commits to protected branches
+  - Base role must be `write`
+  - Branch protection rules will still apply
 - Create protected tags
 - Delete protected tags
 {%- ifversion bypass-branch-protections %}