removing readthedocs.io references (#3294)

We should not refer to readthedocs.io from our docs for content, unless it's absolutely necessary. 
This removes the last readthedocs.io references.

dev_tools/conf/pip-list-dev-tools.txt

@@ -22,7 +22,7 @@ qiskit~=0.13.0
 
 # For generating documentation.
 pypandoc
-recommonmark >= 0.4.0
+myst-parser
 Sphinx~=3.2.0
 sphinx_rtd_theme
 sphinx-markdown-tables

docs/dev/development.md

@@ -1,10 +1,10 @@
-## Development
+# Development
 
 This document is a summary of how to do various tasks one runs into as a developer of Cirq.
 Note that all commands assume a Debian environment, and all commands (except the initial repository cloning command) assume your current working directory is the cirq repo root.
 
 
-### Cloning the repository
+## Cloning the repository
 
 The simplest way to get a local copy of cirq that you can edit is by cloning Cirq's github repository:
 
@@ -24,7 +24,7 @@ If you want to contribute changes to Cirq, you will instead want to fork the rep
 
 
 
-### Forking the repository
+## Forking the repository
 
 1. Fork the Cirq repo (Fork button in upper right corner of
 [repo page](https://github.com/quantumlib/Cirq)).
@@ -62,7 +62,7 @@ Most importantly you should see ```upstream/master``` listed.
     At this point your local git master should be synced with the master from the main cirq repo.
 
 
-### Setting up an environment
+## Setting up an environment
 
 0. First clone the repository, if you have not already done so.
 See the previous section for instructions.
@@ -112,7 +112,7 @@ See the previous section for instructions.
     add2virtualenv ./
     ```
 
-### Protocol buffers
+## Protocol buffers
 
 [Protocol buffers](https://developers.google.com/protocol-buffers) are used in Cirq for converting circuits, gates, and other objects into a standard form that can be written and read by other programs.
 Cirq's protobufs live at [cirq/api/google](https://github.com/quantumlib/Cirq/tree/master/cirq/api/google) and may need to be changed or extended from time to time.
@@ -124,7 +124,7 @@ Additionally, for workflows that use bazel (relevant for C/C++ code depending on
 These rules live in the BUILD files [here](https://github.com/quantumlib/Cirq/tree/master/cirq/api/google/v1) and [here](https://github.com/quantumlib/Cirq/tree/master/cirq/api/google/v2).
 Downstream projects should load Cirq as an [external dependency](https://docs.bazel.build/versions/master/external.html), allowing rules from those BUILD files to be used directly.
 
-### Continuous integration and local testing
+## Continuous integration and local testing
 
 There are a few options for running continuous integration checks, varying from easy and fast to slow and reliable.
 
@@ -276,7 +276,7 @@ dev_tools/docs/build-rtd-docs.sh
 The HTML output will go into the `dev_tools/rtd_docs/sphinx/_build` directory.
 
 
-### Producing a pypi package
+## Producing a pypi package
 
 1. Do a dry run with test pypi.
 

docs/dev/nomenclature.md

@@ -1,4 +1,4 @@
-## Nomenclature
+# Nomenclature
 
 This page describes naming rules and conventions that exist throughout Cirq.
 These rules are important in order to maintain a consistent interface that is 
@@ -8,7 +8,7 @@ users and developers. Please try to use these terms when writing code.
 If you have suggestions for improvements or changes, please create a PR 
 to modify this list or open an issue.
 
-### Quantum computing terms
+## Quantum computing terms
 
 Use `state_vector` to describe a pure state that is passed in as a numpy
 array, numpy tensor, or list of amplitudes. **Do not** use `wavefunction`, 

docs/devices.md

@@ -1,4 +1,4 @@
-### Devices
+# Devices
 
 The ``Device`` class is an abstract class which encapsulates constraints
 (or lack thereof) that come when running a circuit on actual hardware.

docs/install.md

@@ -1,4 +1,4 @@
-## Installing Cirq
+# Installing Cirq
 
 Choose your operating system:
 
@@ -11,14 +11,14 @@ If you want to create a development environment, see the [development page](dev/
 
 ---
 
-### Alpha Disclaimer
+## Alpha Disclaimer
 
 **Cirq is currently in alpha.**
 We may change or remove parts of Cirq's API when making new releases.
 To be informed of deprecations and breaking changes, subscribe to the
 [cirq-announce google group mailing list](https://groups.google.com/forum/#!forum/cirq-announce).
 
-### Installing on Linux
+## Installing on Linux
 
 0. Make sure you have python 3.6.0 or greater.
 
@@ -61,7 +61,7 @@ To be informed of deprecations and breaking changes, subscribe to the
     ```
 
 
-### Installing on Mac OS X
+## Installing on Mac OS X
 
 0. Make sure you have python 3.5 or greater.
 
@@ -102,7 +102,7 @@ To be informed of deprecations and breaking changes, subscribe to the
     ```
 
 
-### Installing on Windows
+## Installing on Windows
 
 0. If you are using the [Windows Subsystem for Linux](https://docs.microsoft.com/en-us/windows/wsl/about), use the [Linux install instructions](#installing-on-linux) instead of these instructions.
 
@@ -135,7 +135,7 @@ To be informed of deprecations and breaking changes, subscribe to the
     ```
 
 
-### Installing on Docker
+## Installing on Docker
 
 This will use a Docker image that will isolate Cirq's installation from the rest of the system.
 

docs/tutorials/examples.md

@@ -100,22 +100,22 @@ Quantum circuit to prepare the BCS ground states for superconductors/superfluids
 
 ## Advanced Tutorials
 
-*    [Variational Algorithm](https://cirq.readthedocs.io/en/latest/tutorials/variational_algorithm.html)
+*    [Variational Algorithm](./variational_algorithm.ipynb)
 Case study demonstrating construction of an ansatz for a two-dimensional Ising
 model and how to simulate and optimize it.
 
-*    [QAOA](https://cirq.readthedocs.io/en/latest/tutorials/QAOA_Demo.html)
+*    [QAOA](./QAOA_Demo.ipynb)
 Demonstration of optimizing cost of a max-cut problem using quantum
 approximation optimization algorithm (QAOA)
 
-*    [Hidden Linear Function](https://cirq.readthedocs.io/en/latest/tutorials/hidden_linear_function.html)
+*    [Hidden Linear Function](./hidden_linear_function.ipynb)
 Demonstration of a problem similar to Bernstein-Vazirani that uses a hidden
 function rather than using an Oracle.
 
-*    [Quantum Walk](https://cirq.readthedocs.io/en/latest/tutorials/Quantum_Walk.html)
+*    [Quantum Walk](./Quantum_Walk.ipynb)
 Demonstration of both classical and quantum random walks that shows their
 similarities and differences.
 
-*    [Rabi Oscillations](https://cirq.readthedocs.io/en/latest/tutorials/Rabi_Demo.html)
+*    [Rabi Oscillations](./Rabi_Demo.ipynb)
 Example of using sweeps and symbols to show rotation of a qubit by different
 angles.

docs/tutorials/variational_algorithm.ipynb

@@ -42,7 +42,7 @@
     "\n",
     "In this tutorial, we will create a [quantum variational algorithm](https://arxiv.org/abs/1304.3061) using cirq and show how it can optimize a simple Ising model.\n",
     "\n",
-    "To begin, please follow the instructions for [installing Cirq](https://cirq.readthedocs.io/en/latest/install.html)."
+    "To begin, please follow the instructions for [installing Cirq](../install.md)."
    ]
   },
   {

rtd_docs/conf.py

@@ -153,7 +153,7 @@ def autodoc_process(app, what: str, name: str, obj: Any, options,
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'recommonmark',
+    'myst_parser',
     'nbsphinx',
     'sphinx.ext.autodoc',
     'sphinx.ext.autosummary',
@@ -272,3 +272,5 @@ def autodoc_process(app, what: str, name: str, obj: Any, options,
 
 # to resolve name clashes between the generated files
 autosummary_filename_map = {"cirq.QFT": "cirq.QFT_deprecated"}
+
+myst_update_mathjax = False