Add cssd upgrade

Author: yuanchuan

bin/handler.js

@@ -2,6 +2,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import os from 'node:os';
 import { stdin } from 'node:process';
+import { execSync } from 'node:child_process';
 
 import { pkg, config, configPath, configDownloadPath } from '../src/static.js'
 import { parse } from '../src/parse.js';
@@ -128,6 +129,11 @@ export function getProgramName() {
     return pkg.bin[name] ? name : 'cssd';
 }
 
+export function handleUpgrade() {
+    console.log('Upgrading CLI...');
+    execSync('npm update -g @css-doodle/cli', { stdio: 'inherit' });
+}
+
 async function read(path) {
     let content = '';
     let error = null;

bin/index.js

@@ -13,6 +13,7 @@ import {
     handleDisplayConfig,
     handleDisplayConfigList,
     handleUseAction,
+    handleUpgrade,
     getProgramName
 } from './handler.js';
 
@@ -100,6 +101,11 @@ program
     .argument('[source]', 'css-doodle source file to parse')
     .action(handleParse);
 
+program
+    .command('upgrade')
+    .description('Upgrade CLI to the latest version')
+    .action(handleUpgrade);
+
 if (process.argv.length <= 2) {
     program.help();
 } else {