Issue #9: Add supporting documentation to track the project history.

-  Rename README.markdown to README.rst.
-  Add AUTHORS.rst with brief note on their contributions.
-  Add CHANGELOG.rst with detailed change documentation.
-  Add CONTRIBUTING.rst with detailed guidelines for pull requests.
-  Fix MANIFEST to include these new files.
-  Ensure setup uses the README.rst for `long_description`.
Merge pull request #10 from lakshmivyas/feature/support-docs

Issue #9: Add supporting documentation to track the project history.