Bump actions/upload-pages-artifact from 1.0.9 to 2.0.0 (#91)

Bumps [actions/upload-pages-artifact](https://github.com/actions/upload-pages-artifact) from 1.0.9 to 2.0.0.
- [Release notes](https://github.com/actions/upload-pages-artifact/releases)
- [Commits](actions/upload-pages-artifact@v1.0.9...v2.0.0)

---
updated-dependencies:
- dependency-name: actions/upload-pages-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -27,7 +27,7 @@ jobs:
           make doc
 
       - name: upload docs artifact
-        uses: actions/upload-pages-artifact@v1.0.9
+        uses: actions/upload-pages-artifact@v2.0.0
         with:
           path: ./docs/_build/html/