Add random_clifford_circuit to API docs (#14072)

* Add random_clifford_circuit to API docs

* Add it also to the circuit module doc

Author: eliarbel

qiskit/circuit/__init__.py

@@ -303,9 +303,10 @@
 * :data:`SessionEquivalenceLibrary`, a mutable instance of :class:`EquivalenceLibrary` which is used
   by default by the compiler's :class:`.BasisTranslator`.
 
-There is also a utility for generating random circuits:
+There are also utilities for generating random circuits:
 
 * :func:`random.random_circuit`
+* :func:`random.random_clifford_circuit`
 
 Finally, the circuit module has its own exception class, to indicate when things went wrong in
 circuit-specific manners:
@@ -1058,6 +1059,7 @@ def __array__(self, dtype=None, copy=None):
 
 .. currentmodule:: qiskit.circuit.random
 .. autofunction:: random_circuit
+.. autofunction:: random_clifford_circuit
 .. currentmodule:: qiskit.circuit
 
 Apply Pauli twirling to a circuit