Tiny tuning help message.

Signed-off-by: Eric Wang <[email protected]>

Author: skygragon

lib/cli.js

@@ -72,7 +72,9 @@ cli.run = function() {
   yargs.commandDir('commands')
     .completion()
     .help('h')
+    .alias('h', 'help')
     .version(false)
+    .epilog('Seek more help at https://skygragon.github.io/leetcode-cli/commands')
     .wrap(Math.min(yargs.terminalWidth(), 120))
     .argv;
 };