Description of the issue
The docstrings for type aliases defined in cirq.circuits.circuit.py are not helpful and should be improved / fixed.

For example:
See https://quantumai.google/reference/python/cirq/circuits/circuit#CIRCUIT_TYPE

Where does the line "INT_TYPE: The central part of internal API." comes from?

The reference pages docstring also looks unrelated to the actual type.

https://quantumai.google/reference/python/cirq/circuits/circuit/INT_TYPE

Cirq version
0.15dev