Changed error to warning on A11y Netlify plugin

Author: Toma Nistor

netlify.toml

@@ -1,14 +1,20 @@
 [build]
-publish = "public"
-command = "hugo --gc --minify"
+  publish = "public"
+  command = "hugo --gc --minify"
 
 [context.production.environment]
-HUGO_VERSION = "0.50"
-HUGO_ENV = "production"
-HUGO_ENABLEGITINFO = "true"
+  HUGO_VERSION = "0.50"
+  HUGO_ENV = "production"
+  HUGO_ENABLEGITINFO = "true"
 
 [context.deploy-preview]
-command = "hugo -b $DEPLOY_PRIME_URL"
+  command = "hugo -b $DEPLOY_PRIME_URL"
 
 [context.branch-deploy]
-command = "hugo -b $DEPLOY_PRIME_URL"
+  command = "hugo -b $DEPLOY_PRIME_URL"
+
+[[plugins]]
+package = "netlify-plugin-a11y"
+
+  [plugins.inputs]
+  resultMode = "warn"