Handle symbolic link to READMEs (BB-6765)
The README.rst is a symbolic link to src/zc/botokeyring/README.rst.
git handles this just fine. :)
It would be great if bitbucket did too and showed the rendered contents as the project overview.
(The README.rst is testable documentation. It's most convenient if it's in the source directory, both for running tests and so it's included in binary Python distributions.)