Add new router helper for relay hints

src/nostr/kinds.ts

@@ -0,0 +1,8 @@
+export const GROUP = 35834
+export const COMMUNITY = 34550
+
+export const isGroupAddress = (a: string) => a.startsWith(`${GROUP}:`)
+
+export const isCommunityAddress = (a: string) => a.startsWith(`${COMMUNITY}:`)
+
+export const isCommunityOrGroupAddress = (a: string) => isCommunityAddress(a) || isGroupAddress(a)