fixes wrong cache type (#688)

Co-authored-by: Lucas Genzelis <lucas@foxbox.com>

src/index.tsx

@@ -31,7 +31,7 @@ const priority = {
     high: 'high',
 } as const
 
-type Cache = 'low' | 'normal' | 'high'
+type Cache = 'immutable' | 'web' | 'cacheOnly'
 
 const cacheControl = {
     // Ignore headers, use uri as cache key, fetch only if not in cache.