Bump readthedocs-sphinx-search from 0.1.0 to 0.3.2 in /docs/source

Bumps [readthedocs-sphinx-search](https://github.com/readthedocs/readthedocs-sphinx-search) from 0.1.0 to 0.3.2.
- [Changelog](https://github.com/readthedocs/readthedocs-sphinx-search/blob/main/CHANGELOG.rst)
- [Commits](readthedocs/readthedocs-sphinx-search@0.1.0...0.3.2)

---
updated-dependencies:
- dependency-name: readthedocs-sphinx-search
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/source/requirements.txt

@@ -1,4 +1,4 @@
 sphinx==3.2.0
 sphinx_rtd_theme==0.5.0
-readthedocs-sphinx-search==0.1.0
+readthedocs-sphinx-search==0.3.2
 docutils==0.16