added comment for the newly exposed function CanonicalDialect

pop.go

@@ -56,6 +56,12 @@ func DialectSupported(d string) bool {
 	return false
 }
 
+// CanonicalDialect checks if the given synonym (could be a valid dialect too)
+// is a registered synonym and returns the canonical dialect for the synonym.
+// Otherwise, it returns the lowercase value of the given synonym.
+//
+// Note that it does not check if the return value is a valid (supported)
+// dialect so you need to check it with `DialectSupported()`.
 func CanonicalDialect(synonym string) string {
 	d := strings.ToLower(synonym)
 	if syn, ok := dialectSynonyms[d]; ok {