The upgrade network should be a installation/configuration step for Standalone Network

[MassimoTambu]

When running a Standalone network with multiple nodes I stumbled upon 'tx_not_supported' error.
After various attempts, the solution was to update the network protocol as shown here in the majority of the running nodes.
In my opinion this is not so intuitive because I followed all the steps to install, configure, publish history and run a full validator node but in these pages there were not any advise or step that tell you something like "If you want to setup a Standalone Network make sure to update the network!".
You have to do this step even if every nodes are running the latest stellar-core version (currently 18) and this is pretty ambiguous.
Note: this step is only required in the Standalone network.

I think this should be written maybe in the running section.
What do you think?