Add sphinx-code-examples to requirements and docs

Added 'sphinx-code-examples' to requirements.txt and updated live_code.ipynb to mention Sphinx-Exercises and Sphinx-Code-Examples for including executable code in exercises and examples. Cleaned up requirements.txt by removing a duplicate git reference.

book/features/live_code.ipynb

@@ -173,6 +173,10 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
+    "## Exercises and examples with executable code\n",
+    "\n",
+    "To include executable code in your book inside exercises and/or examples, you can use the Sphinx extension [Sphinx-Exercises](https://ebp-sphinx-exercise.readthedocs.io/en/latest/syntax.html#alternative-gated-syntax) and/or the Sphinx extension {ref}`Sphinx-Code-Examples <sphinx-code-examples-gated>`.\n",
+    "\n",
     "## Alternative with JupyterLite (less well integrated)\n",
     "\n",
     "Another option to use python in your browser is to use [JupyterLite](https://jupyterlite.readthedocs.io/en/stable/). However, compared to Sphinx-Thebe, described above, this doesn't give a similar seamless interface within your page. Nevertheless, depending on your application, JupyterLite could be a useful tool, especially as it allows for three IDE types: Jupyter Notebook, Jupyter Lab and the iPython REPL.\n",
@@ -181,7 +185,7 @@
     "\n",
     "```{tip}\n",
     "The TeachBooks Team has focused primarily on the use of Sphinx-Thebe and has not looked at JupyterLite over the last couple years. If you have an interesting application of this tool for teaching, please get in touch, we would love to see it! You can use [GitHub Discussions](https://github.com/orgs/TeachBooks/discussions) or sent us an email at [info@teachbooks.io](mailto:info@teachbooks.io).\n",
-    "```"
+    "```\n"
    ]
   }
  ],

requirements.txt

@@ -10,9 +10,8 @@ sphinx-named-colors == 1.0.1
 sphinx-iframes == 1.0.5
 sphinx-prime-applets == 1.0.2
 sphinx-dropdown-toggle == 1.0.0
+sphinx-code-examples == 1.0.1
 
 git+https://github.com/TeachBooks/Sphinx-Thebe
 
-docutils==0.17.1
-
-git+https://github.com/TeachBooks/Sphinx-Code-Examples
+docutils==0.17.1