Updating qec docs (#283)

Updating qec docs

---------

Signed-off-by: Sachin Pisal <[email protected]>
Co-authored-by: Ben Howe <[email protected]>

Author: sacpis

docs/sphinx/components/qec/introduction.rst

@@ -275,7 +275,7 @@ to prototype and develop new codes.
            h(logicalQubit.ancx)
 
            # Measure Z stabilizers
-           for zi in range(len(logicalQubit.ancx)):
+           for zi in range(len(logicalQubit.ancz)):
                for di in range(len(logicalQubit.data)):
                    if z_stabilizers[zi * len(logicalQubit.data) + di] == 1:
                        x.ctrl(logicalQubit.data[di], logicalQubit.ancz[zi])