add Generic Dns
Based on https://github.com/tachiyomiorg/tachiyomi/blob/master/app/src/main/java/eu/kanade/tachiyomi/network/DohProviders.kt
Based on https://github.com/tachiyomiorg/tachiyomi/blob/master/app/src/main/java/eu/kanade/tachiyomi/network/DohProviders.kt