create verb tests

Create a file `tests/verbs.yaml`, formatted like other test yaml files ([an example](https://github.com/apertium/apertium-kir/blob/main/tests/ky-nouns.yaml)).

Include a section for each form of a verb—e.g. "Infinitives", "Past tense forms", etc.—and put all the correct forms of all the verbs currently in the transducer in the correct section.

The goal of this is to find patterns in the verbal morphology that we can implement in the morphology.