Add "copy" button to the sphinx documentation page. (#609)

### Description

Following https://sphinx-copybutton.readthedocs.io/en/latest/ to add a
little “copy” button to the right of the code blocks. Added
`sphinx_copybutton` extension in conf.py.

Tested in local build (`make html`) and it works fine, but I'm not sure
if the `sphinx_copybutton` extension is available on the server where
the website HTML is built.

### Checklist
_Before this pull request can be reviewed, all of these tasks should be
completed. Denote completed tasks with an `x` inside the square brackets
`[ ]` in the Markdown source below:_
- [x] I have added a description (see above).
- [x] I have added a link to any related issues see (see above).
- [x] I have read the [Contributing
Guide](https://github.com/quokka-astro/quokka/blob/development/CONTRIBUTING.md).
- [ ] I have added tests for any new physics that this PR adds to the
code.
- [x] I have tested this PR on my local computer and all tests pass.
- [ ] I have manually triggered the GPU tests with the magic comment
`/azp run`.
- [x] I have requested a reviewer for this PR.

---------

Co-authored-by: Ben Wibking <ben@wibking.com>

.github/workflows/docs.yml

@@ -34,7 +34,7 @@ jobs:
         run: |
           .github/workflows/dependencies/documentation.sh
           python3 -m pip install --upgrade pip
-          python3 -m pip install sphinx==5.3.0 sphinx_rtd_theme sphinxcontrib_bibtex
+          python3 -m pip install sphinx==5.3.0 sphinx_rtd_theme sphinxcontrib_bibtex sphinx-copybutton
 
       - name: Install and Build
         run: |

build_docs.sh

@@ -12,5 +12,5 @@ cd docs
 
 echo "Build the Sphinx documentation for Quokka."
 #make PYTHON="python3" LATEXMKOPTS="-interaction=nonstopmode" latexpdf
-make PYTHON="python3" html &> make_source_html.out
+make PYTHON="python3" html
 cd ../

docs/conf.py

@@ -37,7 +37,7 @@
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = [ "sphinxcontrib.bibtex" ]
+extensions = [ "sphinxcontrib.bibtex", "sphinx_copybutton" ]
 
 bibtex_bibfiles = ["references.bib"]
 #bibtex_default_style = "plain"

docs/requirements.txt

@@ -1,3 +1,5 @@
-breathe==4.31
-sphinx==4.2.0
-sphinxcontrib_bibtex==2.4.1
+sphinx==5.3.0
+sphinxcontrib_bibtex==2.6.2
+sphinx-copybutton==0.5.2
+breathe==4.35.0
+sphinx_rtd_theme==2.0.0