How to activate SSH on Rasbian for Raspberry Pi from first boot?

I have a Raspberry Pi Zero Wireless that i have got to connect to my wifi direct on first bott (see this post) and then i liked to get the SSH activated from the first boot also.

After some searching i find out that you can put a file named ssh without any file extension in the boot partition.

Raspbian then going to activate SSH on the first boot so no need to put in any keyboard and monitor to activate it.

The content of the file doesn´t matter, it could contain either text or nothing at all.