Quantum Circuits (#387)

* Quantum Circuits

* Clarifying explanations.

* update quantumcircuit notebook with circuit resource count

* Moving

Author: jaygambetta

index.ipynb

@@ -52,7 +52,7 @@
     "\n",
     "Terra, the ‘earth’ element, is the foundation on which the rest of the software lies. Terra provides a bedrock for composing quantum programs at the level of circuits and pulses, to optimize them for the constraints of a particular device, and to manage the execution of batches of experiments on remote-access devices. Terra defines the interfaces for a desirable end-user experience, as well as the efficient handling of layers of optimization, pulse scheduling and backend communication.\n",
     "  * [Summary of Quantum operations](qiskit/terra/summary_of_quantum_operations.ipynb) - list of quantum operations (gates, reset, measurements) in Qiskit Terra\n",
-    "  * Using the QuantumCircuit object\n",
+    "  * [Quantum Circuits](qiskit/terra/QuantumCircuits.ipynb) - Gives a summary of the `QuantumCircuit` object\n",
     "  * Compiling and executing a quantum program\n",
     "  * The Transpiler \n",
     "    \n",