Clarify if `ssh_timeout` and `ssh_handshake_attempts` are mutually exclusive

[lindhe]

Description

The documentation says the following:

ssh_timeout (duration string | ex: "1h5m2s") - The time to wait for SSH to become available. Packer uses this to determine when the machine has booted so this is usually quite long. Example value: 10m. This defaults to 5m, unless ssh_handshake_attempts is set.

[…]

ssh_handshake_attempts (int) - The number of handshakes to attempt with SSH once it can connect. This defaults to 10, unless a ssh_timeout is set.

This leaves me wondering:

1. Are the ssh_timeout and ssh_handshake_attempts fields mutually exclusive? It kind of sounds like that, but it's not clear.
2. What is the value of ssh_timeout if ssh_handshake_attempts is set (and vice versa)? (if they are not mutually exclusive, of course).

This should be clarified in the documentation.

I think that the root cause for my confusion is that the default values are explained with so many conditions. If I have understood things correctly, these are the possible states for the default values:

ssh_timeout is set	ssh_handshake_attempts is set	ssh_timeout default value	ssh_handshake_attempts default value
True	True	-	-
False	True	5 min	-
True	False	-	10
False	False	5 min	10

Does this table correctly represent all possible states? If so, I see no reason for all the conditionals in explaining the fields' default values. If my table is correct, we can simply say that "the default value for ssh_timeout is 5 min and the default value for ssh_handshake_attempts is 10".

Use Case(s)

The documentation should be clear on how things works.

Potential References

Originally posted as vmware/packer-plugin-vsphere#289