Add signpost text to the VM endpoint compute settings that explains why a user might want to change the values from the defaults

[zjs]

We provide good defaults, but it may not be clear to a user under what circumstances they would want to change these values or even what reasonable alternative they might pick.

Clarifying the functional result of these values in terms that the VI admin is familiar with may better enable them to make good decisions.

[jak-atx]

@lweitzman can you please take a look here and see where we can add additional signpost text for the fields where we supply default values?

For example we provide a good explanation here:

But not here: