feat(lib): The placeholder handler is now part of the lib

src/lib/placeholder.ts

@@ -0,0 +1,19 @@
+import { Guild, GuildMember, User } from 'discord.js';
+
+export function placeholder(text: string, member: GuildMember): string {
+	const user: User = member.user;
+	const guild: Guild = member.guild;
+
+	const replacements: Record<string, string> = {
+		'{user.mention}': user.toString(),
+		'{user.name}': user.username,
+		'{user.tag}': `${user.username}#${user.discriminator}`,
+		'{guild.name}': guild.name,
+		'{guild.count}': guild.memberCount.toString(),
+	};
+	let output: string = text;
+	for (const key in replacements) {
+		output = output.replaceAll(key, replacements[key]);
+	}
+	return output;
+}