package.json

 {
   "name": "markarth",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "Live preview local Markdown files in the browser",
   "main": "dist/index.js",
   "repository": {
     "type": "git",
-    "url": "https://git.sr.ht/~simulacrumparty/markarth"
+    "url": "https://git.simulacrum.party/simulacrumparty/markarth"
   },
   "bin": {
     "markarth": "dist/index.js"
   "author": "Dylan Baker <dylan@simulacrum.party>",
   "license": "MIT",
   "dependencies": {
-    "argparse": "^1.0.10",
-    "chokidar": "^2.0.4",
-    "express": "^4.16.4",
-    "remarkable": "^1.7.1",
-    "ws": "^6.1.2"
+    "argparse": "^2.0.1",
+    "chokidar": "^3.5.1",
+    "express": "^4.17.1",
+    "marked": "^1.2.8",
+    "ws": "^7.4.2"
   },
   "devDependencies": {
-    "@types/argparse": "^1.0.35",
-    "@types/chokidar": "^1.7.5",
-    "@types/express": "^4.16.0",
-    "@types/remarkable": "^1.7.2",
-    "@types/ws": "^6.0.1",
-    "typescript": "^3.2.4"
+    "@types/argparse": "^2.0.5",
+    "@types/chokidar": "^2.1.3",
+    "@types/express": "^4.17.11",
+    "@types/marked": "^1.2.1",
+    "@types/ws": "^7.4.0",
+    "typescript": "^4.1.3"
   }
 }

src/index.ts

 import { ArgumentParser } from 'argparse';
 import chokidar from 'chokidar';
 import express, { Request, Response } from 'express';
-import Remarkable from 'remarkable';
+import marked from 'marked';
 import WebSocket from 'ws';
 
 import * as fs from 'fs';
 import template from './template';
 
 const parser = new ArgumentParser({
-  version: '0.1.0',
-  addHelp: true,
+  add_help: true,
   description: 'Realtime Markdown preview',
 });
 
-parser.addArgument('file');
-parser.addArgument(
-  ['-p', '--port'],
-  {
-    defaultValue: 1729,
-    help: 'The port to run on',
-    type: 'int' }
-);
+parser.add_argument('file');
+parser.add_argument('-p', '--port', {
+  default: 1729,
+  help: 'The port to run on',
+  type: 'int',
+});
 
-const { file, port } = parser.parseArgs();
+const { file, port } = parser.parse_args();
 const filepath = path.resolve(file);
 
 const getRenderedHTML = () => {
-  const md = new Remarkable();
   const fileContents = fs.readFileSync(filepath, 'utf-8');
-  return md.render(fileContents);
+  return marked(fileContents);
 };
 
 const wss = new WebSocket.Server({