Use reStructuredText for documentation

AUTHORS:
  Renamed to AUTHORS.rst

AUTHORS.rst:
  Add reStructuredText markup

ChangeLog:
  Renamed to ChangeLog.rst

ChangeLog.rst:
  Add reStructuredText markup

README:
  Renamed to README.rst

README.rst:
  Add reStructuredText markup
  Add chanarch release page to the downloads section
Release Chanarch 0.1.1

- Use filesizes from the thread JSON to check if the file is downloaded
  to speed up file downloading
- Use reStructuredText for documentation