Add ping command

src/commands/misc/ping.js

@@ -0,0 +1,17 @@
+import { SlashCommandBuilder } from '@discordjs/builders';
+
+export default {
+	data: new SlashCommandBuilder()
+		.setName('ping')
+		.setDescription('Pong!'),
+
+	interaction: async (interaction, client) => {
+
+		const sent = await interaction.reply({ content: 'Pinging...', fetchReply: true });
+
+		interaction.editReply(
+			`Roundtrip latency:
+			${sent.createdTimestamp - interaction.createdTimestamp}ms
+			Websocket heartbeat: ${client.ws.ping}ms.`);
+	},
+};