If a project has a README file, its contents is shown on the Source "tab". It looks a bit counter-intuitive to me, since README is usually intended (by developers) to be the first thing to be read by users (at least I suppose so).
The typical "workflow" for users looking for some project seems to be like this:

search for some terms, come up with resuts

open Overview project page

read short Description, decide if it's worth attention

look for a more detailed documentation (README)

I think it'd be a good idea to display README content in Overview. Stripped a bit, may be, with a link to full version, or something. I daresay this would make BB just a bit more usable and logical.

Thanks and sorry if it was already suggested, querying issues hasn't yielded anything.