Update sphinx to 1.6.5

[pyup-bot]

There's a new version of sphinx available.
You are currently using 1.6.4. I have updated it to 1.6.5

These links might come in handy: PyPI | Changelog | Homepage

Changelog

1.6.5

=====================================

Features added

• 4107: Make searchtools.js compatible with pre-Sphinx1.5 templates
• 4112: Don't override the smart_quotes setting if it was already set
• 4125: Display reference texts of original and translated passages on
  i18n warning message
• 4147: Include the exception when logging PO/MO file read/write

Bugs fixed

• 4085: Failed PDF build from image in parsed-literal using :align: option
• 4100: Remove debug print from autodoc extension
• 3987: Changing theme from alabaster causes HTML build to fail
• 4096: C++, don't crash when using the wrong role type. Thanks to mitya57.
• 4070, 4111: crashes when the warning message contains format strings (again)
• 4108: Search word highlighting breaks SVG images
• 3692: Unable to build HTML if writing .buildinfo failed
• 4152: HTML writer crashes if a field list is placed on top of the document
• 4063: Sphinx crashes when labeling directive .. todolist::
• 4134: [doc] :file:docutils.conf is not documented explicitly
• 4169: Chinese language doesn't trigger Chinese search automatically
• 1020: ext.todo todolist not linking to the page in pdflatex
• 3965: New quickstart generates wrong SPHINXBUILD in Makefile
• 3739: :module: option is ignored at content of pyobjects
• 4149: Documentation: Help choosing :confval:latex_engine
• 4090: [doc] :confval:latex_additional_files with extra LaTeX macros should
  not use .tex extension
• Failed to convert reST parser error to warning (refs: 4132)

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖