Open-vm-tools option mis-documented in repo, missing from check help

[kfiresmith]

Hi Folks,
Reading the primary documentation for this check here in Github noted that I can use --open-vm-tools to exempt any warnings due to unmanaged VMs - https://github.com/BaldMansMojo/check_vmware_esx/blob/master/README.md?plain=1#L232.

This is slightly incorrect as I pieced together from the release notes of 1.2.4 which states:

Remove output of guestToolsUnmanaged if --open_vm_tools_ok

Beyond being incorrect in the repository documentation, and probably more importantly, it's completely missing from the check command context menus.

I've confirmed that --open_vm_tools_ok with underscores and the 'ok' suffix works on 1.2.5, so that should probably be what is added to the documentation.

Apologies for not doing a PR for this but I'm swamped and it looks like it'll be an easy fix for any current contributor to bang out.