Update config.yaml (#21724)

Author: bllchmbrs

.hyperlint/config.yaml

@@ -18,3 +18,11 @@ reviewer:
     check_status_upon_review_failure: neutral
   limit_num_reviews: 2
   limit_num_comments: 5
+automation:
+  custom_style_guide:
+    enabled: true
+    path_to_style_guide_dir: ".github/styles/plain-text-style-checks/"
+  enabled: true
+  vale_style_guide:
+    enabled: true
+    path_to_vale_ini_file: ".hyperlint/.vale.ini"