Add some state management stuff

src/app/commands.ts

@@ -0,0 +1,15 @@
+import {batch, postJson} from "@welshman/lib"
+import {normalizeRelayUrl} from "@welshman/util"
+import {relayInfo} from "app/state"
+
+export const loadRelay = batch(1000, async (urls: string[]) => {
+  const data = await postJson(`${DUFFLEPUD_URL}/relay/info`, {urls})
+
+  relayInfo.update($relayInfo => {
+    for (const {url, info} of data) {
+      $relayInfo.set(normalizeRelayUrl(url), info)
+    }
+
+    return $relayInfo
+  })
+})