message: adding circuit-optimizer doc
diff: @@ -638,6 +638,7 @@ or in Python
  print(qbits['opt-params'])
  +
  Accelerator Decorators
  ----------------------
  ROErrorDecorator
  @@ -703,6 +704,35 @@ IR Transformations
  CircuitOptimizer
  +++++++++++++++++
  +This ``IRTransformation`` of type ``Optimization`` will search the DAG representation
  +of a quantum circuit and remove all zero-rotations, hadamard and cnot pairs, and merge
  +adjacent common rotations (e.g. ``Rx(.1)Rx(.1) -> Rx(.2)``).
  +
  +.. code:: python
  +
  + # Create a bell state program with too many cnots
  + xacc.qasm('''
  + .compiler xasm
  + .circuit foo
  + .qbit q
  + H(q[0]);
  + CX(q[0], q[1]);
  + CX(q[0], q[1]);
  + CX(q[0], q[1]);
  + Measure(q[0]);
  + Measure(q[1]);
  + ''')
  + f = xacc.getCompiled('foo')
  + assert(6 == f.nInstructions())
  +
  + # Run the circuit-optimizer IRTransformation, can pass
  + # accelerator (here None) and options (here empty dict())
  + optimizer = xacc.getIRTransformation('circuit-optimizer')
  + optimizer.apply(f, None, {})
  +
  + # should have 4 instructions, not 6
  + assert(4 == f.nInstructions())
  +
  Observables
  -----------
  @@ -721,7 +751,7 @@ To use this Observable, ensure you have Psi4 installed under the same
  $ make -j8 install
  $ export PYTHONPATH=$(python3 -m site --user-site)/psi4/lib:$PYTHONPATH
  -This observable type takes an dictionary of options describing the
  +This observable type takes a dictionary of options describing the
  molecular geometry (key ``geometry``), the basis set (key ``basis``),
  and the list of frozen (key ``frozen-spin-orbitals``) and active (key ``active-spin-orbitals``) spin
  orbital lists.
  