Create a Mockito comparison table in README

[f-person]

Is your feature request related to a problem? Please describe.
I think there are people who migrate to mocktail from mockito after migrating their app to null safety. I think the migration process can be simplified so that the developers don't have to read the full documentation.

Describe the solution you'd like
A table in README that maps mockito way of doing things to mocktail way.

Describe alternatives you've considered
Reading the full doc, searching in issues.

Additional context
I came up with this idea when I was looking for argThat alternative in mocktail. I though that someone already had this problem too and went to look it up in this repository's issues. I found it (#68). However, I think that it would be easier to migrate if I had a table somewhere in README mapping mockito usage to mocktail.