cli: Show beta flags in help output
Looks like
```
-r --reuse-window Force to open a file or folder in an already opened window.
-vvv --verbose Enable verbose logging.
--link (beta) Securely bind code-server via Coder Cloud with the passed name. You'll get a URL like
https://myname.coder-cloud.com at which you can easily access your code-server instance.
Authorization is done via GitHub.
```
Based on commits by @JammSpread in #2405
Closes #2396 A
Anmol Sethi committed
affb92f281fe8295694a7f4f31278b5b4751b359
Parent: 6c69300