fix: packageManager flag

Author: yyx990803

packages/@vue/cli/bin/vue

@@ -41,7 +41,7 @@ program
   .option('-d, --default', 'Skip prompts and use default config')
   .option('-c, --config <json>', 'Skip prompts and use inline JSON string as config')
   .option('-r, --registry <url>', 'Use specified NPM registry when installing dependencies')
-  .option('-m, --package-manager <command>', 'Use specified NPM client when installing dependencies')
+  .option('-m, --packageManager <command>', 'Use specified NPM client when installing dependencies')
   .option('-f, --force', 'Overwrite target directory if it exists')
   .action((name, cmd) => {
     require('../lib/create')(name, cleanArgs(cmd))