small doc improvements (#12553)

* small doc improvements

* Update qiskit/quantum_info/operators/symplectic/sparse_pauli_op.py

Co-authored-by: Jake Lishman <jake@binhbar.com>

---------

Co-authored-by: Jake Lishman <jake@binhbar.com>

qiskit/dagcircuit/dagcircuit.py

@@ -544,7 +544,7 @@ def remove_qubits(self, *qubits):
 
     def remove_qregs(self, *qregs):
         """
-        Remove classical registers from the circuit, leaving underlying bits
+        Remove quantum registers from the circuit, leaving underlying bits
         in place.
 
         Raises:

qiskit/quantum_info/operators/symplectic/sparse_pauli_op.py

@@ -54,7 +54,7 @@ class SparsePauliOp(LinearOp):
     :class:`~qiskit.quantum_info.Operator` in terms of N-qubit
     :class:`~qiskit.quantum_info.PauliList` and complex coefficients.
 
-    It can be used for performing operator arithmetic for hundred of qubits
+    It can be used for performing operator arithmetic for hundreds of qubits
     if the number of non-zero Pauli basis terms is sufficiently small.
 
     The Pauli basis components are stored as a

qiskit/transpiler/preset_passmanagers/__init__.py

@@ -109,12 +109,12 @@ def generate_preset_pass_manager(
     This function is used to quickly generate a preset pass manager. Preset pass
     managers are the default pass managers used by the :func:`~.transpile`
     function. This function provides a convenient and simple method to construct
-    a standalone :class:`~.PassManager` object that mirrors what the transpile
+    a standalone :class:`~.PassManager` object that mirrors what the :func:`~.transpile`
     function internally builds and uses.
 
     The target constraints for the pass manager construction can be specified through a :class:`.Target`
-    instance, a `.BackendV1` or `.BackendV2` instance, or via loose constraints (``basis_gates``,
-    ``inst_map``, ``coupling_map``, ``backend_properties``, ``instruction_durations``,
+    instance, a :class:`.BackendV1` or :class:`.BackendV2` instance, or via loose constraints
+    (``basis_gates``, ``inst_map``, ``coupling_map``, ``backend_properties``, ``instruction_durations``,
     ``dt`` or ``timing_constraints``).
     The order of priorities for target constraints works as follows: if a ``target``
     input is provided, it will take priority over any ``backend`` input or loose constraints.