Docs: Fix intersphinx_mapping (#1110)
Docs: Fix intersphinx_mapping (#1110)

Sphinx documentation has moved from https://www.sphinx-doc.org/en/stable/ to https://www.sphinx-doc.org/en/master/

Fixes the command line message:
```
intersphinx inventory has moved: https://www.sphinx-doc.org/en/stable/objects.inv -> https://www.sphinx-doc.org/en/master/objects.inv
```
snide/sphinx_rtd_theme,snide/sphinx_rtd_theme,snide/sphinx_rtd_theme,snide/sphinx_rtd_theme