cEP 0: Replace markdown for cEPs

markdown is a crazy language. rST is slightly better, and that aligns better with being a Python org.

However, we should be a multilingual org, so it is useful to force ourselves to switch languages, testing different bears in the process.

For one, asciidoc has better table support.
http://www.methods.co.nz/asciidoc/newtables.html