Speed up has_print_function.

This speeds up parsing significantly for large files.

Update render.py (Fixes typo in the word dictionary.)

Fixes typo in the word dictionary.

add regression test for complex number

Copy of Handle spaces before comments

Fix markdown syntax for link to code of conduct

This allows comments that are preceded by a space to be detected
and processed with the comment

Remove dead code from render.py module

Convert readthedocs links for their .org -> .io migration for hosted projects

As per [their blog post of the 27th April](https://blog.readthedocs.com/securing-subdomains/) ‘Securing subdomains’:

> Starting today, Read the Docs will start hosting projects from subdomains on the domain readthedocs.io, instead of on readthedocs.org. This change addresses some security concerns around site cookies while hosting user generated data on the same domain as our dashboard.

Test Plan: Manually visited all the links I’ve modified.