Consider HTTP 429 a succcessful response in the Markdown link check. (#2201)

Co-authored-by: Matt Dale <[email protected]>

Author: alcaeus

.pre-commit-config.yaml

@@ -49,6 +49,9 @@ repos:
   hooks:
     - id: markdown-link-check
       exclude: ^(vendor)
+      # If the endpoint returns HTTP 429 (Too Many Requests), consider it a
+      # successful check.
+      args: ["-a 200,206,429"]
 
 - repo: local
   hooks: