doc: enable sphinx-copybutton extension

The sphinx-copybutton extension adds a button to every code snippet
that, when clicked, copies the code to the clipboard.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>

doc/conf.py

@@ -82,6 +82,7 @@ extensions = [
     "zephyr.doxyrunner",
     "zephyr.vcs_link",
     "notfound.extension",
+    "sphinx_copybutton",
     "zephyr.external_content",
 ]
 

scripts/requirements-doc.txt

@@ -7,6 +7,7 @@ sphinx-tabs
 sphinxcontrib-svg2pdfconverter
 pygments>=2.9
 sphinx-notfound-page
+sphinx-copybutton
 
 # YAML validation. Used by zephyr_module.
 PyYAML>=5.1