[validators] confirmation of correct flags and procedures

[coesensbert]

It's been very long since we have added/removed validators to tfchain, for any net. Our docs and procedures are probably outdated. That was definitely the case regarding validator keys, but this is resolved now here: https://docs.grid.tf/threefold/itenv_threefold_main/src/branch/master/grid_operations/grid_tfchain#re-inserting-re-setting-session-aura-gran-keys-to-same-as-controller-account

These are some of our old docs on adding/removing validators: https://docs.grid.tf/threefold/itenv_threefold_main/src/branch/master/kubernetes_clusters/hagrid-prod2/applications/tfchainmainnet/Adding-validators.md https://docs.grid.tf/threefold/itenv_threefold_main/src/branch/master/kubernetes_clusters/hagrid-prod2/applications/tfchainmainnet/Removing-validators.md

This is related to:

• https://github.com/threefoldtech/grid_deployment/issues/52
• https://github.com/threefoldtech/grid_deployment/tree/development/tfchain-validator/mainnet

Can dev confirm:

• are these procedures still valid? If not we should make new ones and test
• are these flags correct for a validator node? -> https://github.com/threefoldtech/grid_deployment/blob/development/tfchain-validator/mainnet/docker-compose.yml#L25-L44