Update redirect instructions in netlify.toml

Author: Stefterv

netlify.toml

@@ -1,6 +1,6 @@
 # Netlify redirects
 # 1. To add a subdomain, add a redirect in this file first and merge the PR
-# 2. Add the subdomain to the Processing website in netlify
+# 2. Add the subdomain to the Processing website in netlify by going to Domain Management -> Production Domains -> Add domain alias
 
 [[redirects]]
   from = "https://wiki.processing.org/*"