Update Documentation

[olgabot]

Adds a curated table of context to the sidebar and updates logos and images to use the local versions

Before you submit a pull request, check that it meets these guidelines:

• The pull request should include tests.
• If the pull request adds functionality, the docs should be updated. Put
  your new functionality into a function with a docstring, and add the
  feature to the list in README.md and README.rst.
• The pull request should work for Python 2.7, 3.4, 3.5, and 3.6.

Fixes #[issue-number-here].