docs: update readme with related tool (#428)

Author: sbdchd

README.md

@@ -198,6 +198,7 @@ Note the `files` parameter as it specifies the location of the files to be linte
 - <https://github.com/stripe/pg-schema-diff>
 - <https://github.com/kristiandupont/schemalint>
 - <https://github.com/supabase-community/postgres-language-server>
+- <https://github.com/premium-minds/sonar-postgres-plugin>
 
 ## related blog posts / SE Posts / PG Docs