Add caching

internal/config/v1.go

@@ -41,9 +41,11 @@ func (z *ZurgConfigV1) GetCacheTimeHours() int {
 }
 
 func (z *ZurgConfigV1) GetDirectories() []string {
-	var rootDirectories []string
+	rootDirectories := make([]string, len(z.Directories))
+	i := 0
 	for directory := range z.Directories {
-		rootDirectories = append(rootDirectories, directory)
+		rootDirectories[i] = directory
+		i++
 	}
 	return rootDirectories
 }