Document how to run nebula on Windows

[jasikpark]

nebula.exe -service

also add this to the help menu

[csawyerYumaed]

This is my quick and dirty guide

create a folder C:\nebula

extract the zip file there, including the dist\ folder

copy over your config.yml file and keys
make sure you have tun device setup in the yaml:

tun:
 disabled: false
 dev: tun0
 drop_local_broadcast: false
 drop_multicast: false
 tx_queue: 500
 mtu: 1422

if you do not, you will get an error about tun parameters wrong or something.

start powershell as administrator
cd \nebula
./nebula.exe -service install

check the service from the services app(search services from the start/win menu) as administrator: then scroll down to nebula that will let you start/stop the service if needed.

It will also show you the command line it's running, so you can run it yourself and debug any issues that crop up.