Add explanation for resolving product name linting issues (#475)

vale/Grafana/Spelling.yml

@@ -2,6 +2,10 @@ extends: spelling
 message: |
   Did you really mean '%s'?
 
+  For product names, the Grafana dictionary might not know of it yet.
+  You need to add an entry to https://github.com/grafana/writers-toolkit/tree/main/vale/dictionaries/en_US-grafana.wordlist to add a product name to the dictionary.
+  Alternatively, raise an [issue](https://github.com/grafana/writers-toolkit/issues/new?title=Grafana.Spelling%20%3A%20%3CWORD%3E) and a maintainer will add it for you.
+
   For UI elements, use [bold formatting](https://grafana.com/docs/writers-toolkit/write/style-guide/style-conventions/#bold).
   The spell checker doesn't check words with bold formatting.