feat(pages): add /application/[guildId]/[channelId] (#4)

cypress/fixtures/guilds/[guildId]/channels/get.ts

@@ -0,0 +1,12 @@
+import { guildExample } from '../../guild'
+import { Handler } from '../../../handler'
+import { channelExample, channelExample2 } from '../../../channels/channel'
+
+export const getChannelsWithGuildIdHandler: Handler = {
+  method: 'GET',
+  url: `/guilds/${guildExample.id}/channels`,
+  response: {
+    statusCode: 200,
+    body: [channelExample, channelExample2]
+  }
+}